Hey, what do youguys think. Its a 1981 chevy 1/2 ton, 4.11 auburngear rear end and a 2,200 stall convertor, Motor is a 355 with world S/R heads, roller rockers, dual plane intake with a jet performance stage 2 quadrajet.. What do youguys think of this cam.. engine is believed to be stock rebuilt bottom end..

Dual Energy Hydraulic Flat Tappet Cam & Lifter Kit
Adv. Duration: 275°/277°
Duration @ .050: 219°/229°
Lift: .462''/.482''
RPM Range: 2000-6000 |

Would this work ok or do i need to take one step down, the engine has a slight lope to it now and makes great power to 5,500 and starts to float at 5,700 or so.The engine will free rev to 6,100 rpms no problem (didnt wanna take any higher, hehe),.i would like to be able to rev to 6,000 or so.. Thanks..

I'd figure out what compression you have know...its pretty much a shot in the dark without knowing that.

If you want a little more power you can always look at my cam...I have a 355 and the world heads as well. Those 4.11s will be screaming for a bit bigger can I would think.

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81 Z-28 355 Home Ported World S/R Heads(1.94/1.5) XS268 solid cam (230/236@.050, .477/.488 Net Lift), 650@ DP, Tremec TKO 5-speed, 3.42s, Nitto Drag Radials. 13.4@102.9 w/ 1.95 60ft time.

Yes, you really need to know your actual CR. like AllGo mentioned or we are guessing.

But I will guess and say that if you have 4-notch flat-tops, (b/c it's .030" over and I doubt if they went back in with dished pistons), 67 cc heads standard .025" down in the hole pistons and a .039" or so thick headgasket you are right at 9.42 to 1 CR.

At that CR., AND the fact you want to run to 6,000 and maybe some above, I would run a good old CC 270 Magnum Solid lifter cam AND no more then a cheap $25/set of Z-, (-142), valve springs!!

It will run good, imho...

However, IF by chance you are down around 8.5 to 1 CR. or so b/c you have dished pistons, then go with something like an XS262S, again a solid lifter cam!!

I am partial to solid lifter cams and don't mind lashing them every so often b/c they rpm great AND they generally produce about 4 percent more power then a same spec. equivalent hy-cam all through the rpm range!!

And don't worry about the 5800 rpm b/c a solid lifter cam will rpm as far as you have nerve enough to hold it down b/c it can't pump lifters up and float!! (With good valve springs like the Z- springs are, imho)... OR go with what CC recommends in the way of springs!!

pdq67

Thanks guys for the recommendations.. Im gonna hafta try again to get ahold of the engine builder.. i know the heads are 76cc world products S/R heads, but im not so sure about the pistons as they were only $79 or so on the reciept and i dont really wanna pull the heads just to find out compression ratio..(if i wasnt in a time crunch id swap these out for some better heads while i was at it, but im in a $$$ and time crunch... Thanks again guys.. nate

Well, i finally was able to get ahold of engine builder.. Engine is 9.1:1 compression, has 4 vr flat tops with 76cc which makes 9.1.. was decked and balanced too.. HE said he installed a Comp 260 camshaft.. Said its a proven 320 horsepower at flywheel as hes built this same combo for lots of offroad guys.. So youguys think i should stay with this cam or go one step biger to a 268?? Thanks.. nate

Yes, a good old CC 268HE and Crane 272/272 Energizer AND the already mentioned, (by me), CC 270 Magnum solid will do you nicely, imho...

I'd go with the solid lifter cam and good Z- springs and not look back..

pdq67

There's a Comp. Cams XE274 K-kit with your name on it if you want it. http://www.nastyz28.com/ubb/wink.gif

Glad to hear you got a hold of Bob. Can't believe he remembers that engine.

Boy doug, You just have everything i need dont you?? hehe.. Ill take that cam kit from you, was just looking at the specs.. I think that would work out really good.. I hope the springs will fit in the S/R heads though.. So you have my carb and now the cam i need. hehe.. Better get my butt in gear and start getting you some money huh?? hehe.. Thanks doug, Ill give you a call this weekend... Nate

Personally, I would rather have at a min, 9.5 to 1 for a 274 cam and preferrably almost 10 to 1 CR..

And with that said, I'm backing up and saying that I figure the 270 Magnum solid cam is about the largest one to use at 9 to 1, and better yet, the 260HE AND 268HE/272/272 Energizer...

(I think the 268HE and 272 Energizer are almost identical except for the way they are checked is all)...

AND another one at this CR. is Cranes 266/266 Energizer! It will be powerful in your more like the 260HE only a schosh higher rpm'med is all...

pdq67

Aight, im gonna think this over and see what i can come up with.. Doug has everything i need, but only if it was a xe268 and not a 274... I wonder if the local performace shop would trade me for a xe268 if i got the k kit from doug.. Im gonna hafta think about it.. Thanks guys.. nate

Shave the heads or better yet take these Darts off my hands; they're 64cc, 215 runner, etc. http://www.nastyz28.com/ubb/wink.gif Then you'll probably want something bigger to take advantage of the flow potential. http://www.nastyz28.com/ubb/biggrin.gif Pretty soon you'll want the cheater sys. ....

See, there was a plan in selling that truck to you. http://www.nastyz28.com/ubb/wink.gif http://www.nastyz28.com/ubb/biggrin.gif http://www.nastyz28.com/ubb/wink.gif http://www.nastyz28.com/ubb/biggrin.gif

Please see what I just posted at "Wasting my money"..

It's all in the Dynamic/Effective Compression Ratio..

pdq67

WHOAAA, CAn you say Full Roller rockers,new plugs and a oilchange in one sentance?? this thing just came to life.. Spent about 3 hours installing and adjusting the roller rockers from my other engine on this engine.. The thing just came to life.. Revs MUCH faster/smoother and the top end power went nuts.. This engine in my 2wd truck is gonna be freakin insane...Still needs a bit more cam though...

BTW doug, you did con me into this didnt you.. I hate to admit this to you but when someone has a buncho stuff that i want.. I Normally get it.. Ill talk to you this weekend about my not really needed performancee oriented spending spree problems...LOL.. Nate

PDQ, FOr now i think im gonna stick with the cam thats in it, or if i get a wild hair up my butt i might stick in that 268HE or one like it.. been thinking that i kinda wanna stick with hydro since i dont really have the cash when i do the engine swap for some expensive name branded rockers and some better spings... Ill save all the expensive stuff for the 406 im gonna be bulding.. THanks man.. Nate