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View Full Version : L98 in 87 corvette Help?



Swags63
05-26-2008, 04:49 PM
I'm looking for some help with my neighbors 87 corvette. It has the L98 engine in it, he is looking to do a rebuild or crate engine build up with the limiting factor being the rear end and possibly the computer in the car. I believe the rear end will take around 400 hp???? it is a newly rebuilt Dana 36. Can anyone help steer us in the right direction. I'm limited on info for this combination.:goof:confused

BadAzzGTA89
05-26-2008, 04:55 PM
This will work!
ZZ4 Crate Engine 350CI 355HP HO with Aluminum Heads
http://www.crateenginedepot.com/store/images/24502609_large.jpg
Or this
FastBurn 385 Crate Engine 350CI/385HP with Aluminum Vortec Heads
http://www.crateenginedepot.com/store/images/12496769_large.jpg

Poncho
05-26-2008, 05:00 PM
Keep in mind though, there still is legwork to be done to utilize the stock intake AND allow the car to actually breathe up top.

Prince Valiant
05-27-2008, 12:03 PM
Depends on how trick you want to be...on a car like that, one of the limiting, but not impossible factors will be controlling the engine. If you want wild, then finding someone who could burn chip's for you is the answer.

The good imo on the l98's is that the stock heads are fairly decent and can support HP, plenty of bolt on stuff available, and decent ecu friendly cams available.

The bad is the stock intake...it's designed to really enhance low and mid range performance....the long relatively narrow runner's become a hinderance above 4500-5000rpm. The stock cam is pretty tiny too hence the need to upgrade.

This is what I'd probably do (with options in parentheses):
Find a good short block with ~ 9.5-10:1 CR/balanced/etc. Stick with 350 (350-358) ci since that'll give you the best chance of working with the stock stuff. A 383 would almost certainly demand reprogramming.
Go with some edlebrock performer cylinder heads (they have some for l98 applications...it's ~ 900/pair, so if cost is a concern, just go with stock heads and 5 angle valve job with back cut valves).
Go with comp cams 08-530-08 Cam (206/212 @ .050, .477/.471 lift, 115 LSA) which should work with your ecu, yet is a healthy step up from stock.
For an intake, I'd find the old accel super ram manifold (need a base and pleum/runners) of ebay or a swap meet...or failing that, you can have the stock stuff modified (ported, port matched).
Go with a ACCEL twin 58mm throttle body. (You could sub twin 52 for milder combo if sticking with stock heads).
Go with long tube headers w/ 1 5/8th diameter.
Paired with decent ignition components, free flowing exhaust, this should be a very strong l98. With the increased rev potential afforded from the new heads/intake/bigger cam, it's likely you will need to do some programing (ie chip burning), but there are people out there who can accomplish this. I'd estimate an engine like this would easily put out 350hp net.

280-300 if you stuck with stock heads/intake/upgraded cam/rest of bolt-ons...and that should work with the stock ecu fine.

The nice thing about above is that everything works with the 87 engine/corvette....

PonyKiller87
05-27-2008, 12:36 PM
What kind of a budget is he on?

I would suggest buying the SDPC 350 or building something similar.
http://www.sdparts.com/product/SD360VTPI/360HPTPIVortecCustomHighPerformanceSeriesStreetand StripEngine.aspx

The super ram is nice but there getting hard to find and the prices are nuts. You can do well with a ported stock plenum and bigger runners. After that the base plate is the real restriction in the system. I wouldn't go with anything bigger than a 52 mm TB until you get to more HP. The stock TB flows well enough to support the rest of the TPI system.

Your most likely going to end up needing a tune of some kind to make it run well.

Personaly I like the TPI system, I like the way it looks, I like the low end power it makes... but if your not attached to keeping TPI don't. Its a huge PITA.

forest
05-27-2008, 02:12 PM
Ive got the stuff to tune it, ( thanks Kevin)

PB86MCSS
05-27-2008, 08:43 PM
I would also look into Vortec heads/intake as a budget combo with a better cam to go on the L98, although the Vortec/TPI intake isn't cheap :) . The stock TPI intake setup is limiting, depending on what you want to do....and I agree, TPI is a PITA, at least in my case. I sometimes wish I kept it CCC Q-Jetted, ran smoothlessly and would of accepted just as much power in stock form, basically. Not saying there aren't benefits though. Once you start doing aftermarket intake stuff (Super Ram/ Mini Ram) it starts to get pretty costly for what you're getting out of it. JMHO.

BadAzzGTA89
05-28-2008, 07:16 AM
Use a carb that is all:rolfj/k

Mr. Brett
05-28-2008, 11:08 AM
I had an L98 powered IROC and it was fun for what it was, but I never would have spent any money upgrading the engine with the TPI still on there. Either replace the whole thing or don't bother. Otherwise I second the carb idea....