View Full Version : single pattern versus dual pattern cams - is one "better" for street apps?


76_TypeLT
10-01-2010, 03:51:30 PM
So please excuse the noobie question, I am still learning more about cams (and other things). In the Vizard book I am reading, he is a proponent of single pattern cams (particularly for street type applications). As I am browsing cam companies' catalogs I see that pretty much all off-the-shelf cams are dual pattern (at least for hyd roller "street" cams I am looking at). Is there some reason that I don't see any single pattern cams? I am sure this is not a question that can be answered easily, but maybe the more relevant question is why would someone choose single over dual (or vice versa)?

From my catalog browsing, it seems like the cams that would be most appropriate for my build have 6-8* more exhaust duration @ 0.050.

I know I can get any cam grind that I'd want, so mostly curious why all I see in the catalogs are dual pattern.

Thanks for helping me better understand all this!

489cid
10-01-2010, 04:05:41 PM
The main reason for dual patter cams as explained to me was the longer duration on the the exhaust side was to cover up the shortcomings of the head design. The exhaust side needs help to keep up with the intake. which sounded good to me, but could just be a pile of bs.

hhott71
10-01-2010, 04:17:52 PM
Both have been successful in the SBC.
Find one that has the proper intake duration you need and the exhaust will be fine with the wisdom of the cam designer.

76_TypeLT
10-01-2010, 04:29:46 PM
Both have been successful in the SBC.
Find one that has the proper intake duration you need and the exhaust will be fine with the wisdom of the cam designer.

I see, interesting.

So not necessarily a huge advantage to running one versus the other in your opinion?

high impact
10-01-2010, 04:43:41 PM
IMO if this is a street car then it doesn't matter much. Choose what works best for your total combination and the engine's intended use. Torque is what is most important in a street car along with everything matching the power band. I think most new cam profiles from reputable companies will be dual pattern as they attempt to squeeze every bit of power out of them.

CNC BLOCKS
10-01-2010, 04:48:39 PM
We use a lot of single pattern cams for most of ou builds more so when we are running a tight lobe seperation like 108 or 110

Wider lobe seps do require more exhaust lobe from what I have seen.

I see alot of guys who have good flowing heads like AFR's who will put a 10 split in them which kills the lower end and mid range.

We build a lot of circle track engines and some of those engines require a single pattern cam do to the good exhaust they run.

Here is a quote I did on another site on a HYD roller for a guy and we have seen very good results using this cam.

Pual along with my PM here is another cam that we have used with great sucess I would go with this one.

HR283/370 283 232 156 .3700 .000 CTA

Break down is

cam lift int .370 ex. 370
Adv. duration 283 283
duration @.050 232 232
durations at .200 156 156
gross lift 1.5 .555 .555
gross lift with 1.6 .592 .592

CTA
The first letter is either "C" for a conventional shaped nose on the lobe.

T" (Torque)for lobes suited for lower RPM or motors with numerically low rocker ratios.

A" for asymmetrical lobes (opening and closing ramps different). Asymmetrical lobes usually have a slower closing rate to help prevent valve bounce.

This cam we have ground on a 108 lobe sep where your using a standard transmission and going to a 110 lobe sep would broaden your torque curve out. Your heads flow pretty good and need some lift to move more air.

We have used a lot of single pattern cams and on the dyno they make extremly good low end torque and strong mid range top end power. And with your low compression that cam will build better dynamic pressure over the crane cam you posted.

We have our cams done with the ever wear Dist gear as mentioned.
Carl

76_TypeLT
10-01-2010, 05:58:22 PM
Good feedback, thanks. So for a street machine, it's not much of an issue (if any).

CNC BLOCKS
10-01-2010, 06:28:26 PM
Good feedback, thanks. So for a street machine, it's not much of an issue (if any).

We run tighter lobe seps with single pattern cams ans so far on the dyno we proved it works!!!

Good luck

Todd80Z28
10-01-2010, 07:53:21 PM
I thought it was basically about the cylinder head. I've seen it written that heads with high exhaust/intake flow ratios benefit from single patterns, whereas heads with weaker ratios require the split that favors the exhaust.

I've done both with my engine- a single pattern first, and a wide split later. I have Trick Flow G1 heads, that flow 230-240 on the intake, and close to 200 on the exhaust. That's a high ratio, 80%. I ran the Comp 268HE for the first several years (218*, .454" lift), and then moved to the ZZ4 hydraulic roller (207/222*, .479"/.514") that's still in there. Overall, I think I had better throttle response with the single pattern. One thing I do know- I *CANNOT* make the engine happy unless it is idling fairly rich- it stumbles all over itself otherwise. Pipes are sooty on the inside, and I have tinkered for years trying to fix. I think it's over-scavenging because of the strong exhaust port. I'd like to go to a single pattern roller (something like Comp's 270HR 215*, .500") to see how it feels in comparison.

That's just one experience, though, not a pro builder's.

wookie
10-01-2010, 09:07:13 PM
Nitrous likes extra duration and lift so we use split pattern cams on spray engines.

Rich Schmidt
10-01-2010, 09:20:50 PM
Nitrous likes extra duration and lift so we use split pattern cams on spray engines.


Nitrous also likes a wider lobe seperation angle and less overlap. Its hard to decrease the overlap and still get good exhaust blowdown without adding duration to the exhaust lobe. Another consideration is that you typically dont need to be real agressive with the exhaust lobe. A softer ramp rate has no real downside on the exhaust lobe other then increased overlap. In the case of the intake,the more agressive you can make it the better so you can cram more lift in as the piston approaches BDC wiithout needed to add as much duration after BDC. So the intake lobe is typically going to have faster ramps then the exhaust.

76_TypeLT
10-01-2010, 10:37:01 PM
We run tighter lobe seps with single pattern cams ans so far on the dyno we proved it works!!!

Good luck

for what type of application? or are you talking in general?

Damon
10-01-2010, 11:31:09 PM
My experience has been that single pattern cams often feel snappier becuase they make more torque in a given RPM range. Typically a fairly tight LSA (~110*, give or take- certainly much tighter than any stock application would use) and moderate duration (mainly chosen by your desired RPM range) make for a killer stoplight-to-stoplight torque curve. This seems to be true even if the exhaust port is weak relative to the intake port, but definitely true if you have a good exhaust port.

I think about increasing exhaust duration in a way similar to choosing LSA. The wider the LSA or the more exhaust bias in the cam the more you "stretch" the usable RPM range of the cam. But both come at the expense of peak torque. (Nitrous, supercharged and turbocharged are totally different animals- I'm talking only about N/A combinations)

This is not a "good" thing or a "bad" thing. More of an application-specific thing. I love snappy engines on the street but realistically, most true street cars don't have the traction off the line or the gearing splits further down the track to take advantage of a narrow torque band. So sometimes "cheating" the cam specs with a slightly wider LSA and more exhaust bias actually makes it go quicker over the whole quarter mile. Less chance of spinning out of the hole, faster recovery between the top of one gear and the bottom of the next.

If you think about this stuff too long your head will explode. One of those situations where it's better to try a few different cams than to agonize over the decision. Ask the cam companies to get you in the ballpark but don't expect them to magically have the exact right answer for what's going to give your particular combination the fastest time down the 1320.

night rider
10-02-2010, 05:30:30 AM
Its a matching game.

You need your duration and LSA to match your engine and compression but also the RPM range you will use said engine in.

The split in intake/exhaust then needs to be looked at.

Whats the intake and exhaust flw of your heads, whats your intake system and whats your exhaust system.

You use the split to help over come a short fall on induction ir exhaust side of engine.

Like the vortec heads.. Real good intake ports, weaker exhaust port. If those heads are used with std street car exhaust system and common induction system.. You will gain more power with a 8-12* higher exhaust duration

AFR heads.. The exhaust ports are so good, if you use more duration on exhaust side than intake you kill power.. Now with AFR heads a very limited due to class rules or something induction system, like a 2bbl carb with them, having alittle more duration on intake side than exhaust can gain a toch of power

CNC BLOCKS
10-02-2010, 09:12:10 AM
for what type of application? or are you talking in general?

About all the cams we are asymetricle which we factor in and most of our street cams are in the 108 lob sep which with tighter lobe seps does give you enough over lap to clean the cylinder out. Cams with a wider lobe sep need a bigger split and so to higher RPM that run up arond 8000.

Most of our engines we build with the AFR's need no split but we are working a 415 build with a set of 220 AFR's we may go to a 4 degree split on that engine.

A months ago we build a Dart 400 with set of 210 AFR's with a single pattern solid roller it made peak torque 515 at 4900 RPM and at 6900 RPM made 570 horse. And we used the World intake with the turtle in the bottom.

One other thing is the intake some of the air gap type intakes have small CSA which hurts the top end from what we have seen.

Our circle track engines we run mostly 106 lobe sep and we use high scavange exhaust systems and split pattern cams do not work with these exhaust systems.

Some of our 2 barrel engine we may run a reverse pattern cam on short track where more torque is needed..

Here are two links to look over and these both engines have single pattern cams and hyd.

http://www.chevelles.com/forums/showthread.php?t=106715

This link the engine we used a 2925 intake and the lobe sep was 110 the other was an air gap.

http://www.chevelles.com/forums/showthread.php?t=236517

rtanner
10-02-2010, 09:51:28 AM
if its a pretty mild 350 in that 76 lt, your in texas so i assume air, its hard to beat a comp 268h!!!! for a daily driver cruiser!!!

76_TypeLT
10-02-2010, 11:25:09 AM
if its a pretty mild 350 in that 76 lt, your in texas so i assume air, its hard to beat a comp 268h!!!! for a daily driver cruiser!!!

the plan is to install a 383 with AFR 195 heads (among other things). This is going to be more of a weekend toy and not a daily driver, so want it to have some "umph" but nothing overly obnoxious. Just as an example, the Comp XR282HR has been suggested as a profile to look at as a starting point for what I am looking to get out of my motor, which is a fun motor with more emphasis on the low end of the RPM range. I don't think I will do much strip racing in this car, just not my thing. I am building it to have some fun at the track, so won't get above 6000 RPM too often.

But I have much more research to do. I have to be true to myself and decide how I really think I will drive this car and go from there.

Re: the heads - I have always wanted to try the AFR 195s and think that will allow me to try other things down the road if I want.

NYH1
10-02-2010, 03:18:40 PM
When I called Lunati last winter for a cam recommendation for my setup the tech mentioned two different cams. One was the cam I went with which is their dual pattern Voodoo 262/268 hyd. flt. tap. cam in my sig. below. The other was a single pattern cam with the same intake duration. I think it had a 110 LSA instead of the 112 LSA that my cam has.

I've read that the Vortec heads can use a little help on their exhaust side so I figured I'd go with the dual pattern cam. The tech at Lunati agreed, but said either cam would work well.

70RS_L48
10-02-2010, 11:06:38 PM
the plan is to install a 383 with AFR 195 heads (among other things). This is going to be more of a weekend toy and not a daily driver, so want it to have some "umph" but nothing overly obnoxious. Just as an example, the Comp XR282HR has been suggested as a profile to look at as a starting point for what I am looking to get out of my motor, which is a fun motor with more emphasis on the low end of the RPM range. I don't think I will do much strip racing in this car, just not my thing. I am building it to have some fun at the track, so won't get above 6000 RPM too often.

But I have much more research to do. I have to be true to myself and decide how I really think I will drive this car and go from there.

Re: the heads - I have always wanted to try the AFR 195s and think that will allow me to try other things down the road if I want.

I too am going to use the AFR 195's for my next build. The XR282HR is a great grind. Buy it (or the Crower, Isky, Lunati, Crane equivalent) . Install it. Enjoy it. Heck, I'm running a flat tappet that's roughly equivalent in my current 350 (XE274H - same durations, less lift) and it's a blast. Great street car, great torque and it never sees the high-side of 6k RPM anymore. I just don't see any reason to go bigger in a fun street car that sees little track use. Not to mention that your extra 23-odd cubes will idle better with the same cam specs.

My nickel.

CNC BLOCKS
10-02-2010, 11:49:57 PM
the plan is to install a 383 with AFR 195 heads (among other things). This is going to be more of a weekend toy and not a daily driver, so want it to have some "umph" but nothing overly obnoxious. Just as an example, the Comp XR282HR has been suggested as a profile to look at as a starting point for what I am looking to get out of my motor, which is a fun motor with more emphasis on the low end of the RPM range. I don't think I will do much strip racing in this car, just not my thing. I am building it to have some fun at the track, so won't get above 6000 RPM too often.

But I have much more research to do. I have to be true to myself and decide how I really think I will drive this car and go from there.

Re: the heads - I have always wanted to try the AFR 195s and think that will allow me to try other things down the road if I want.


Thats kind of a low lift cam for a nice set of heads and those AFR's don't require any split in duration.

Here is a quote from another site on a cam I suggested for a 383

Pual along with my PM here is another cam that we have used with great sucess I would go with this one.

HR283/370 283 232 156 .3700 .000 CTA

Break down is

cam lift int .370 ex. 370
Adv. duration 283 283
duration @.050 232 232
durations at .200 156 156
gross lift 1.5 .555 .555
gross lift with 1.6 .592 .592

CTA
The first letter is either "C" for a conventional shaped nose on the lobe.

T" (Torque)for lobes suited for lower RPM or motors with numerically low rocker ratios.

A" for asymmetrical lobes (opening and closing ramps different). Asymmetrical lobes usually have a slower closing rate to help prevent valve bounce.

This cam we have ground on a 108 lobe sep where your using a standard transmission and going to a 110 lobe sep would broaden your torque curve out. Your heads flow pretty good and need some lift to move more air.

We have used a lot of single pattern cams and on the dyno they make extremly good low end torque and strong mid range top end power. And with your low compression that cam will build better dynamic pressure over the crane cam you posted.

We have our cams done with the ever wear Dist gear as mentioned.

Good luck which ever way you go
Carl

76_TypeLT
10-03-2010, 11:49:57 AM
I appreciate all the feedback guys :) As I said, I am still learning more about the ins and outs here in trying to make the best decision possible. Obviously where I am still ignorant is in deciding how much LSA my cam should have, how much overlap, how much lift, etc. I know those AFRs can take more cam and lift, but my question is "do I NEED that?" My "fear" is that I don't want to get stuck with a motor that is useless below 2000 rpm. But I also don't want to get heads that I won't outgrow if I want to step things up down the road.

76_TypeLT
10-03-2010, 11:53:53 AM
Carl, is that cam a custom grind you guys had made for one of your builds?

CNC BLOCKS
10-04-2010, 09:46:25 AM
Carl, is that cam a custom grind you guys had made for one of your builds?


That is a lobe we picked from their list of grinds. As we based that off our HYD flat tappet cams and those cams reallly worked great.

Todd80Z28
10-04-2010, 01:41:05 PM
What about the 282HR with 1.6 rockers, if the low lift is a concern?

76_TypeLT
10-04-2010, 02:35:44 PM
What about the 282HR with 1.6 rockers, if the low lift is a concern?

with 1.6 rockers the lift would be 0.544 and 0.555 with the 282HR. Is that considered "low" for those heads? I have no idea what is "too low". :confused:

So I dropped off my front hubs at a local machine shop to get drilled for some larger wheel studs and was talking to the main guy there. They were recommended by a few mechanics I trust, so I also wanted to feel them out for engine work I am going to need done. I was telling him my goals for my 76 and he really thought I should at least consider going with a 355 over a 383, which I admit I have not thought about doing. Main reason I was thinking about the 383 was to get something with more torque but still having a reliable motor. He said, in general, that a 355 would be more reliable, which is something to consider for a primarily street driven car.

My problem is that I have NEVER driven a car a "hopped up" motor, so I really have no basis to make a decision. I am sure just about anything I put in my 76 would put a smile on my face. I am going to pull my hair out trying to decide what to do. :mad:

grasmo
10-04-2010, 03:45:58 PM
i did a cam profile comparison on the comp. cams site. what i recall was the cams with different timing provided better idle, better idle vacuum, and the engine will come on the cam quicker with a little top end rpm sacrifice. more of a streetable application. cams with the same timing were more of a strip type profile. i assume they do their tests with all other things being equal.

79RedZ
10-05-2010, 01:29:55 PM
with 1.6 rockers the lift would be 0.544 and 0.555 with the 282HR. Is that considered "low" for those heads? I have no idea what is "too low". :confused:

So I dropped off my front hubs at a local machine shop to get drilled for some larger wheel studs and was talking to the main guy there. They were recommended by a few mechanics I trust, so I also wanted to feel them out for engine work I am going to need done. I was telling him my goals for my 76 and he really thought I should at least consider going with a 355 over a 383, which I admit I have not thought about doing. Main reason I was thinking about the 383 was to get something with more torque but still having a reliable motor. He said, in general, that a 355 would be more reliable, which is something to consider for a primarily street driven car.

My problem is that I have NEVER driven a car a "hopped up" motor, so I really have no basis to make a decision. I am sure just about anything I put in my 76 would put a smile on my face. I am going to pull my hair out trying to decide what to do. :mad:


I would have to question his thinking about the 355 is more reliable than a 383. Cubic inches don't make reliability. Proper assembly and good machining is whats going to make your engine reliable. You can throw as much money as you want at your engine but if it isn't put together properly you'll have expensive scrap metal. just my .02 cents worth.

76_TypeLT
10-06-2010, 08:31:47 PM
Perhaps "reliable" is not the best paraphrase for what he was telling me, which is what I was doing. His main point (which I am sure of ;)) is that he thinks I should at least consider a 355 if I am thinking about a 383. That's just going to require more research on my part and talking to more people who actually have these motors.

Todd80Z28
10-06-2010, 08:53:22 PM
Personally, if you want an engine that's useful below 2000 rpm, I'd drop back to something like the 276 or even 270HR. I won't sacrifice the low end of my setup (95% of it's life has been <1900rpm) for a few ponies up top, so I always lean conservative on duration.

olstyle
10-06-2010, 09:13:24 PM
Hopefully by Thanksgiving I'll have my XE276HR 355 up n running.

CNC BLOCKS
10-06-2010, 10:12:42 PM
Personally, if you want an engine that's useful below 2000 rpm, I'd drop back to something like the 276 or even 270HR. I won't sacrifice the low end of my setup (95% of it's life has been <1900rpm) for a few ponies up top, so I always lean conservative on duration.

Here is a link to a 383 build we did that has a HYD flat tappet 284 ADV and 232@ .050 it made 422 foot pounds of torque at 2900 RPM and at 4200 RPM it had 501 on the torque.

http://www.chevelles.com/forums/showthread.php?t=106715

76_TypeLT
10-06-2010, 10:48:27 PM
Hopefully by Thanksgiving I'll have my XE276HR 355 up n running.

it would be very interesting to see how you like this in your 74.

I am getting paralysis by analysis - it's a fault of mine. I am psyching myself out because I worry about putting a motor in my 76 that is overly sluggish/sloppy below 2000 rpm. So like Todd said, I think I am going to have to find a cam with less duration that solves that "problem", which will mean some power lost at higher RPM. Ultimately I think having a motor that can still function < 2000 RPM is going to be more important to me than having extra high RPM power.

And I didn't intend on taking this thread down this "therapy session" road, but I appreciate the input and advice. :)

olstyle
10-06-2010, 11:20:59 PM
I would not worry about some power lost at high rpm's for the street.
My engine was built for circle track racing and didn't start to make power till 3000 rpm's. The cam was for 3000 to 6000 rpm's, not very streetable. I can't wait to see how this 276HR works from 1500 to 5800 rpm's. She should be much more streetable and a whole new beast :bowtie:

Todd80Z28
10-07-2010, 12:12:17 AM
Here is a link to a 383 build we did that has a HYD flat tappet 284 ADV and 232@ .050 it made 422 foot pounds of torque at 2900 RPM and at 4200 RPM it had 501 on the torque.

http://www.chevelles.com/forums/showthread.php?t=106715That's stout, no doubt about it, but what did it make at 1700, and can it cruise down the interstate on a slight incline at that RPM at 65-70mph without loading up and requiring a downshift?

Woody will tell you he's happy with the way his 230* cam pulls in his 355 in 6th, but I've always been wary. Especially when you're messing with a carb- the loss of the low RPM vacuum signal to the carb can make driving the car normally a miserable experience.

CNC BLOCKS
10-07-2010, 09:17:57 AM
That's stout, no doubt about it, but what did it make at 1700, and can it cruise down the interstate on a slight incline at that RPM at 65-70mph without loading up and requiring a downshift?

.

I am sure that engine has more torque then any stock 350 carburated engine at 1700 as this was built for daily driver and the customer seems to be really happy with what he's has. And I am sure its geared properly as well.

76_TypeLT
10-07-2010, 10:19:33 AM
I would not worry about some power lost at high rpm's for the street.
My engine was built for circle track racing and didn't start to make power till 3000 rpm's. The cam was for 3000 to 6000 rpm's, not very streetable. I can't wait to see how this 276HR works from 1500 to 5800 rpm's. She should be much more streetable and a whole new beast :bowtie:

Right, I think having a motor that will have good torque/hp across the 1500-5500 range would be more realistic for me. I think a small part of me has this "dream" of making some sick street car, but I think that would get old pretty fast for the way I intend on enjoying my 76.

I can't wait to see how your new motor runs too :)

muscl car
10-07-2010, 03:29:41 PM
i'm running a dual pattern cam on the street and it runs really good ..........oh and it is 43 yr old technology . the GM #140 cam 257/269 @ .050 493/512 lift 112 LSA 4200 to 7200rpm

79RedZ
10-07-2010, 03:39:24 PM
Perhaps "reliable" is not the best paraphrase for what he was telling me, which is what I was doing. His main point (which I am sure of ;)) is that he thinks I should at least consider a 355 if I am thinking about a 383. That's just going to require more research on my part and talking to more people who actually have these motors.

Gotcha. Read more into than I should have.

I say build the 383 with the AFR heads. Put a 2 piece timing cover on it so that if your not happy with the cam you can change it a little easier. I'll agree with you that you can over think the cam situation, did it myself.

Most importantly though, build the engine that YOU want. joel

76_TypeLT
10-07-2010, 05:39:09 PM
Gotcha. Read more into than I should have.

I say build the 383 with the AFR heads. Put a 2 piece timing cover on it so that if your not happy with the cam you can change it a little easier. I'll agree with you that you can over think the cam situation, did it myself.

Most importantly though, build the engine that YOU want. joel

Nope, you read it completely right - I just typed the wrong thing. :) Any motor can be reliable, you are 100% correct.

thanks for the advice Joel, I'll get it figured out someday, LOL!

76_TypeLT
10-07-2010, 05:45:23 PM
I actually do have another noobie question. When reading cam specs, it lists the RPM range as "2000-6200" or whatever. What does that imply about sub-2000 RPM operation? That it's just going to be "sluggish" below that RPM level? I am sure that is a general RPM range spec and not the end all-be all.

EricsZ28
10-07-2010, 05:52:42 PM
In the stated range of my cam (dual pattern XE274 - it has a range similar to your example), my 383 pulls hard. When I mash the gas below the stated range, it doesn't pull as hard. You can feel the engine come on strong as I hit the lower end of that range.

muscl car
10-07-2010, 06:17:53 PM
In the stated range of my cam (dual pattern XE274 - it has a range similar to your example), my 383 pulls hard. When I mash the gas below the stated range, it doesn't pull as hard. You can feel the engine come on strong as I hit the lower end of that range.


same here with my cam as it does pull pretty good down low but when it is at about 4k rpm it really wakes up and you can definately feel it really pull hard

76_TypeLT
10-07-2010, 10:46:02 PM
So the low end of a cam's stated RPM range is more of a "your motor won't start pulling until you get to ~XYZ rpms". Like I said, I'm a noobie :D

EricsZ28
10-08-2010, 09:56:18 AM
So the low end of a cam's stated RPM range is more of a "your motor won't start pulling until you get to ~XYZ rpms". Like I said, I'm a noobie :D

Sort of. It also depends on the rest of your combination too. Your cam must match your heads, intake, carb, and ignition - they all work together. Then you must select the appropriate gears/stall to match your setup.

Put a small cam in a motor with huge heads and a single plane intake and it may be very lazy in the lower RPM's. By the time the heads and intake start to flow, the cam doesn't provide enough lift to gain the benefits...

This is probably over simplistic, and the pro's may cringe at this, but here is how I setup my combo (along with lots of coaching from people here along the way):
My specific cam range is 1800 to 6000 RPM's. I selected a dual plane intake with a similar RPM range. I opt'd for heads with 185cc runners (which better match my cam and RPM range than the heads with larger runners). I selected gears that gave me a good starting line ratio based upon my shift point (6k to 6.25k). I picked a clutch that could handle leaving the line at 2400 RPM's (no big deal). Then, I picked a carb that gave me enough CFM's at 6250 RPM's (using an online calculator). At that point, the factory timing curve on the HEI wouldn't cut it, so I upgraded the ignition to spin higher and get the timing curve I needed.

My only miss was that I should have gone with the road race version of the TKO600. For me, I've had to spend a lot of time tuning my setup to use overdrive. Unless I'm going 2k RPM's or higher in overdrive, the engine was lazy. The numerically higher OD ratio of the RR TKO600 would have helped... Fortunately, I can tune around this.

FatnLow
10-08-2010, 03:04:06 PM
Analysis paralysis. Been there done that. You were asking about below the stated engine rpm on the cam card that is why it is all about the combination. You'd want at least a 2500-3000 stall converter to get you up there quick or drop the clutch at a higher rpm. This goes hand in hand with your rear gear also. A 4:10 gear will be much more forgiving than a 2:73 when it comes to a cam with a range of 2500-6000. I'd go for the 383 with the afr heads and 282hr cam. That would be fun with the right gears and converter.

76_TypeLT
10-08-2010, 04:48:42 PM
I plan on going with a 5 speed manual and 3.73 gears, which I know others have matched with a 383 (in general here) and love the combo.