Ashton W

We all hear about the conventional lsx swap into basically everything today. Horses ranging from 350 to 600+ and torques that are just as wild. Unfortantly that is what we DO hear about the most. I'm was originally thinking of an LS3 swap with a T56 conversion for my '89 Iroc and have been for many months now but I'm starting to lean towards something different. With the recent release of Chevy's newest turn key engine, the zz6, last November at SEMA, it's turning into and very hard decision. I could either build my own LS3 or I can order a zz6 from Chevy. What do y'all think would be the best option and especially what do you think of the new zz6??? Thanks guys and or gals!

truckerz

iTrader: (2)

Zz6 would be easy, but I'm my opinion very overpriced. Granted you get a warranty, but you could bid your own gen1 sbc for half what they are charging. It does not NEED 4bolt mains or a forged crank. The fast burn heads are not nearly as good as a set of profilers or AFR.

It's nice, but if you cleaned up a junk yard block and put the parts together yourself, you could save enough to buy a transmission and rear end with the savings.

The cool thing about the LS swap is that power comes easy, as they are very responsive to power upgrades.

Really though, it's always up to you, and what your goals are. 400 crank hp is pretty easy with an gen1. Unless you need or really really want the warranty, I say clean up a good block put some AFR195 heads, a xfi280 cam, some afr 8019 Springs some flat top pistons and a HSR intake. Get it tuned well and you'll see over 400 hp at the crank.

zraffz

The ZZ6 has been discussed in the Tech section.

We pretty much came to the conclusion it is an overpriced, slightly improved L31 350 Vortec motor with a cam.

For the price you could build a 383 in the 500 hp range.

Or you could squeak in an LQ4/LQ9 with a cam if you hunt for parts but I don't think it will offer anything more than a properly built 383 without better heads.

five7kid

iTrader: (14)

While you indicated some possibilities you have considered, you didn't give us the most important information: What is the car? What engine/induction did it have from the factory and what does it have now? What will you be using the car for? Do you have to go through emissions inspection or testing? What other modifications do you have planned?

I can't recall anyone building their own LS3. What were you planning on starting with? The LS3-based crate engines are pretty impressive in their own right (and the lowest HP version is less than the ZZ6 cost, with more HP).

Regardless of what you do, I think it's safe to say an LS swap will be more expensive and more work. Swap mounts, wiring, and exhaust pretty much guarantee that. There are aftermarket products to support all that (the GM "Connect and Cruise" packages are impressive), but you'd better be prepared to slap down the plastic.

Some people think "everybody is doing an LS swap now", so they're going to stay "old school". Fine. If that's what you want. For sure Gen I will be less expensive in the short run, but when you match HP to HP, the game starts to change. If you don't like oil leaks, then "old school" isn't for you (my LS engines are the most leak-free I've ever had, and I'm not **** about oil leaks). It's pretty hard to beat the driveability and fuel economy of the EFI LS engines for the power levels they produce. It is a bit disappointing GM chose to stick with the old ZZ3/4 cam in the ZZ6, as it isn't all that great (just another $300 or so for you to do it right).

Bottom line, we can give you all sorts of opinions and observations, but only you know what you're really after.

Ashton W

Well you do make some pretty impressive points. I guess this would have been good to know so here it goes; I have an '89 Iroc-z28 with the 5.7 350 l98 TPI. Everything is completely stock. Unfortantly it's been sitting in an uncovered storage lot for far to long and I'm hoping to be pulling it out here soon. I want the car to have some horses but it didn't need to be like blow my mind away. What I'm coming to understand is that the car just need a major overhaul. I'm just stuck on the countless options out there. I defiantly know that I want to put a forth gen T56 in. That's a positive but yet like I said, I mainly want it to be a street driver/looker. It all just depends upon final cost overall. Thanks for the input!

five7kid

iTrader: (14)

I was rebuilding carburetors before most of you were born. I'm a moderator on the Carburetor forum. That said, I do not now own a vehicle with a carburetor. And I have no intention of going back.

What I would suggest is you look for a long block (assuming you decide not to rebuild your L98) and retain EFI. TPI isn't a "bee's-knees" system, but it isn't hopeless, either. A Holley Stealth Ram solves the main weakness of the system, long runners that limit RPM power (aftermarket base and runners help, but cost a lot more than the Stealth Ram). A ZZ6 long block would actually be a decent choice, as the cam is EFI-friendly (sell off the intake manifold, distributor and water pump that come with it). But I'm sure your L98 could be rebuilt with new cam for a lot less (rebuild the shortblock, add Fast Burn heads and ZZ6 cam, and you'll have basically the same thing as the ZZ6). The thought of a new engine is pretty enticing, though. Add headers and cat-back and you'll have a nice-running, respectable car.