All,

I've got a line on two engines- a '96 LT4, 45k miles out of a Grand Sport, or a 2006 5.3 L33 (the 315hp, all-aluminum 10:1 compression version).

The LT4 is a little spendy- I'm still trying to talk him down to $3500. He doesn't want to, because he paid $4k.
The L33 is $2500, a pullout from a transit-damaged '06 Silverado. 2019 miles.

LT4 would be drop-in, figure out fuel delivery, and go. My LT1 T56 bolts right up. Heck, my small-block headers will work.
L33 would be typical LSx conversion. Need FBody oil pan, flywheel, LS2 intake, probably swap over to different accessory drive, etc. I figure $3000 or so in conversion parts.

Which way would you go?

Todd

Oh, tough call. From scratch I'd go with the 5.3, but considering where you are, the LT4 might be more cost effective in the long run. That exact 5.3 scenario was my plan for my 67, because I had nothing. Then I got this LS1 Z28 to take apart...

With tuning (and the 5.3 is more tunable) the 5.3 will probably be clsoer to 345+ hp, and is lighter.

You getting a trans with that LT4? If so, what one?

Do either come with accessories, etc.?

It is just a matter of how a difficult of a swap you want to handle. The LT4 is a drop in deal minus wiring and computer, but that is easily solved. The L33 would take quite a bit to just make it work in the second gen with all the extra accessories needed. It would be better there to just go with an LS1 or other LSx engine.

With that low mileage, I would jump at that opposed to some 50,000 mile abused LS1. Assuming that price includes harness, ecm and accessories. It is still stronger than any stock 2nd gen SBC. The LS1/f-body accessories might be needed - they seem to package easier, and the truck intake looks taller - I won't state that as fact.

You could always update later, the hard work would be done.

You want a 1 month project or a 6 month project? ;)

L33 with Maggie = 500hp

You want a 1 month project or a 6 month project? ;)LOL. That's right where I'm at.:)

I'm torn. I'd really prefer the 5.3, but I know that I'll be into it for AT LEAST $6000, if not upwards of $8000, by the time it's all done. I'm probably looking at $1500 over the LT4 cost to get it cost (tank mods, ECM reprogram, etc). I get -100lbs with the 5.3.

Plans for the 5.3- install the 2001 Z06 cam and springs, and call it good. I'm thinking I can get a used LS2 intake pretty easily to swap out the truck intake, and the FBody accessory brackets aren't crazy expensive. I'll have to spend some coin on an LS1 bellhousing, input shaft and front case to convert over my T56.

No trans with either engine. Both are complete engine, with ECM, harness and accessories.

I am with Scott Again. But i am biased a bit to the LS engines. I have worked with way too many and still cant figure out why one isnt in one of my Z28s. Oh yeah, too busy working on other peoples shit;)

I might be a bit biased but I love the second Gen V8s, hmmm I wonder why. The problem I see, is that the LT4 may need some new components or rebuilding in a couple of miles or just a freshen up before you install it.

Either way, you will still be ahead money wise with the LT4, you may even be rolling down the road with it shortly after taking delivery of the LT4.

Keep us posted on what your decision is!

Todd, what are you planning to do with the car? I think you'd be happy with an LT4 if you're looking for a nice mod to a driver car. For the amount of money you'd have in an LSX swap (and you'd only have 5.3L at that), you could do the LT4 with a blower or something and make some serious power.

I'd do the LT4 and play with the left over money.

Power isn't my primary goal. If it were, I'd just go with a crate LS2.

The 5.3 will likely equal the power of the LT4. These LSx motors are STRONG, and the 5.3 is no exception.

I want-

1. Good driveability- getting tired of the carb game.
2. Better/no exhaust smell- again, getting tired of the carb game.:)
3. Same or better fuel economy.
4. A bit more power than I have now (which is enough to take me 13.9 in the 1/4).
5. Weight reduction, if possible. The 5.3 will be 100lbs less on the nose.
6. Stop leaking oil ALL OVER the garage from the rear main seal.

The guy with the LT4 is still whining about my offer, so it's probably out. I like the LT4 for the rarity, and the ease of install compared to the 5.3 is a slam-dunk.
To be honest, the 5.3 is what I'd prefer, but the LT4 is intriguing. LT1- I won't bother. It's just that there are a lot of unknowns in the cost of the 5.3 that are holding me back. I don't have an unlimited amount of time to play either, like I used to.

Decisions, decisions. Maybe I should just get a ZZ383 crate. That would get me #4&6 at least, and I could do it in a long weekend.:D

You could come to the Darkside, also.

You could come to the Darkside, also.No chance. I don't want the car to pivot around the engine. I have a front-wheel drive car if I want to experience that feeling.:D

I wouldnt do either one. If youre going to go with an LSx engine, either go wit the full LS1 or spend the money on the LS2. If you want an LT type motor go for the LT1 it has a MUCH better aftermarket. There isnt much difference between LT1 and LT4 except I think the heads and intake, and almost all upgrades available are made for the LT1 style engine. I dont think they even make superchargers for the LT4 do they? Plenty of LT1's to go around, cheap.

LT4s aren't that great. Just because the guy overpaid doesn't mean you have to follow. LT1's are cheap. I have one with the 4L60E that I can't seem to get $1200 out of. With some porting & a little cam, you can easily blast past the LT4 level. There seems to be a problem with bearings going out if you put a bigger cam on the stock bottom. I think it's the tight stock clearances. You could do a cheap overhaul & still be money ahead & you'd know what you have. Check impalassforum & camaroz28 for lots of info.

ask those guys with Lt1's and LT4's how they like the Optispark . I would try to hold out till you can find an LSX motor with the trans you want to cut down on chasing the trans stuff seperatly. a 6 litre would be cool too.

Doug

I haven't done either, but opinion-wise I'd say the LS engine. Camaros were meant to have light, high winding small blocks in them. Got to get that truck cam out of there, though(I think you mentioned swapping cams if you bought the LS engine).

LT engines seem like sort of a bridge between the original SBC they built for what, 30 years? and the all aluminum LS engines. The LS was a full redesign, the LT more of a response to Chevy outsourcing the ZR1 engine design to Lotus. I don't think everyone was happy with the reverse coolant flow LT engine, I've heard arguments that it went opposite the direction the coolant should flow for bubble minimization. Plus like the others said, plenty of problems with the early Optisparks, although it seems like the later ones have done better with the vent hole(no problems so far with my '96 Impala, and as far as I can tell my '95 Formula, with 172,000 miles, has its original Optispark unit).

For my LT1 swap I am making the optispark go away. I am replacing it with a normal external coil HEI distributor. The differences between the LT1 and the LT4 is that the LT4 has: 1.6 rockers, hollow intake stems, different head and intake design (port and chamber size mainly), a four bolt main (LT1 is a two bolt main) and a different cam.

Once again I suggest if you were to decide on the LSx engine as your way to go then wait on hold on for a real LS1. The L33 would require too much to swap over. By the time you are done just getting the engine to look like an LS1 for the swap you would be beyond the price of purchasing the LS1.

Some of these things about the LTx engines are described in greater detail here:

http://www.automotiverebuilder.com/ar/ar99928.htm

"Real LS1s" are getting real old, so to speak. They seem to be fetching big money on Ebay- well over $3000 for one with 60k+ miles. I'd rather be down 40 horse and save $500+ on a virtually new engine.

LS2 is a $10000+ undertaking, so that's out.

To get the L33 over to "fits right in" by LS1 standards, I'll need-

1. Intake- used LS2 intake ought to work. $200
2. FBody accessory brackets- $200~ish from Scoggin-Dickey
3. LS1 flywheel- $300 for a new Fidanza aluminum piece. I could give $100 for somebody's old one, though.
4. Exhaust manifolds- buy somebody's 01-02 FBody pieces. $150? maybe.

Am I missing anything?

Todd,
Your missing an oil pan, about $100-150 used for an F-body oil pan.

When an LS1 costs about 2500-3500 and a 5.3 costs $600-1200, it's rpetty easy to justify the small loss of cubes.

You can also use the truck accessories but have to mod the water pump when using a car intake according to some who have done this swap.

Exhaust manifolds are CHEAP and not a problem.

What Jake said.

Plus if you decide to go bigger & better later, you've done all the hard work. Just buy a long block. :) Or drop a magn. on it and go to 500hp.

"Exhaust manifolds are CHEAP and not a problem." - Indeed. Guys throw them away when they get headers. The last few year LS1 manifolds flow better, I have read.

A recent model 5.3 tuned will do 350+ hp no problem. Add that to the weight reduction. With gears, you are flying.

Interestingly, I'm reading that virtually all the 5.3s can be bored 3mm to match the 99mm bore of the LS1. They're probably using the same cylinder liners for both.

No chance. I don't want the car to pivot around the engine. I have a front-wheel drive car if I want to experience that feeling.:D

It is SO MUCH FUN.

Try it, you don't know what you're missing.

Everyone of the BBC guys, apply peer pressure to Todd.

We've jumped off the bridge, now it's your turn:crazy:

Try it, you don't know what you're missing.

Everyone of the BBC guys, apply peer pressure to Todd.


I'm a BBC fan but there are some cases where a BBC just isn't the engine of choice.
A well tune LSx can in many ways match the performance of most mild BBC's and outperform it for fuel mileage, etc.

I plan to do several more LSx swaps in the next couple of years on just my personal vehicles.

Optispark problems are overblown. 100,000+ thousand miles with no problems is quite common. You want the vented design & replace the vacuum harness when doing the job. The rotors tend to blow up @ 6,500+; MSD has a rotor/cap kit now for about $150. They also have a complete distributor for about $450. Or Dynaspark for $600 addresses all of its problems.

I have 116k on my 96 Impala SS. I have not had any problems with my LT1. Take care of them and they will last a long time. There a few people in the national club that have well over 200k on there original motors and it still pull like it was new. My Impala is the first car that I have not had to work on anything motor related. Areas to watch are intake bolts(loosen and oil leaks start), exhaust manifold bolts(GM used crappy bolts tend to break), if water pump starts to die and leak, the leak will be right on the opti vent hole(good one GM)and may kill the opti. There are guys running 500+ hp on an other wise stock motor with no problems. The weak link in the drivetrain is the 4L60e unless built up. There are guys on their 3 or 4 trannies with an almost stock motor. The LT4 just has a better cam and intake over the LT1. Best bet is find a LT1 from a 94-96 Impala SS, Caprice 9C1, or Buick Roadmaster less HP but more torque than the Camaro/Corvette LT1

So what about going with a carb on the 5.3L. The new Car Craft has a tech article on a carbed 6.0 ( which is what I am looking for to put in my '55), but I was wondering if the 5.3 would make decent power this way as well. Any input?

I was under the impression that the 5.3s, and all truck motors had iron blocks...?.. Did they change that in the new models?
Cause as Jake said.. I'd be all over that over a costly 5.7!

I think the new trucks, the cars & trailblazers have aluminum ones.

I think the new trucks, the cars & trailblazers have aluminum ones.
Yep.