Small Block & Big Block Chevy Specific - L98 Questions

Is the L98 engine basically a SB chevy with crap fuel injection on it? Can I buy Chevy 350 parts for this engine or do the parts need to be L98 specific?

I just picked up a 91 camaro and I wanted to get rid of the FI and do a H/C/I swap. Do you guys have any suggestions?

Its exactly the same except for that it is a 1 piece rear main seal and has the newer style intake manifold bolt pattern.

I wouldn't get rid of the EFI though. Work with it as it can make some good power, you just have to get a good intake for it.

It actually has TBI on it...I'm not really sure where it came from or why they put it on there. The plan is to have the heads worked over and get a custom grind cam. I think if we do that a carb will work better than the TB. The plan is 400 CHP. Does that sound about right?

Thanks for the info on the block though...that is exactly the info I was looking for.

Rather than have those heads reworked you may want to look into the L98 vette motor heads as they were aluminum and a bit better design. They are fairly inexpensive as well. The L98 motor was a stout motor...the 91 GTA trans am I had with a stock L98, TPI airfoil, Magnaflow muffler (not catback, just muffler), and 78,000 miles made 233rwhp and 327rwtq. They were rated at 245hp and 345tq as I recall. Not LS1 numbers but still respectable.

Rather than have those heads reworked you may want to look into the L98 vette motor heads as they were aluminum and a bit better design. They are fairly inexpensive as well. The L98 motor was a stout motor...the 91 GTA trans am I had with a stock L98, TPI airfoil, Magnaflow muffler (not catback, just muffler), and 78,000 miles made 233rwhp and 327rwtq. They were rated at 245hp and 345tq as I recall. Not LS1 numbers but still respectable.

Those are very respectable numbers.

Thanks for the suggestion...I will look into the Vette heads. They are cheaper to port anyways.

There isn't anything actually wrong with the TPI setup. It's just designed to make power down low and in the mid range. There are options out there for upgrading it through several companies. If you just want to go carb you can use virtually any SBC parts. The stealth ram and the offerings from TPIS are popular with the GEN 1 guys that have a little cash to spend on induction.

Quick question, what is the code for this (http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_127626_-1) engine?

Are you sure that was a L98 350 TPI to start with? I am an ex-thirdgenner and it would have been alot of work and money to make an L98 into a TBI to ultimately make the car slower. Is the 8th digit in the VIN 8 (L98 350 TPI), F (LB9 305 TPI), or E (LO3 305 TBI)?

... and just my 2 cents but TPI kicks ass, it is alot of fun to work with and can build alot of power.

I ran a 14.4 @ 96 in my L98 stock. With full bolt-ons I ran 13.8 @ 101.

My car is pretty built now, I ran a 10.9 @ 130. with a lot of nitrous lol, but my L98 has forged internals and that mofo has taken a beating. Even before my forged internals I was running a 150 shot, and countless times i've over-revved it and it still kept on ticking, and still runs great. RELIABLE motor.



Note: Mods in my sig aren't my real mods lol, I have a lot more.

Quick question, what is the code for this (http://www.jegs.com/webapp/wcs/stores/servlet/product_10001_10002_127626_-1) engine?


I'm picking the car up tonight so I'm not 100% sure what engine it is. I just assumed it was the L98 because it was in a 91Z. I'll post the numbers as soon as I get them.

Its a straight car, good paint with a 350 for $1000. The interior looks damn nice too. Maybe the engine came out of a different car? I guess I'll find out tonight.lol

I would really look into what engine it is. The ONLY option for a 350 in a third gen was the L98 and it has the spider looking intake on the top of it. If it is anything else, I would start looking to see if the car is a real Z28, and I would find out what the engine is and what happened to the original engine.

It ended up being the L98. The engine runs strong. So I'm pretty happy.

It ended up being the L98. The engine runs strong. So I'm pretty happy.

Be careful, L98s and their much lesser LB9 (305) brethren are visually identical. In 1991 L98 cars were all automatics and never had t tops so if it has either of those things than you know one of these things are true:

1. The car actually has a 305 (LB9)
2. The engine IS an L98 but it isn't the original engine
3. It may have been converted from an automatic to a manual trans
4. It could have dealer installed t tops

i have personally owned 3 91/92 z28s 5.7 with t-tops and crused Rankin rd,westhiemer etc.my best bud had a 90 formula 350 w/t-tops that got totalled. many passes at HRP with all our cars