Small Block & Big Block Chevy Specific - Third time around L98
10-20-2010, 11:36 PM
I might have the chance to buy the 89 l98 Trans am GTA that my Dad owned for 4 years and put almost 165,000 miles now. The car is sitting still with the stock engine. It has over 300,000 miles on it. Reportedly runs if I put a starter on it. Has the stock transmission and rear end. The rear end is an australian 9 bolt. The body is great, paint not so much, all weatherstripping and seals need replaced, interior is shot, needs tires cuz they are BALD AND DRY ROTTED, probably brakes etc...
I have been wanting to build one with my minimal skills so maybe this is the right car? I will be able to afford to have work done on it.
Here's my question... What should I do with the engine? I know that I want Low 12's minimum.Would love to have a stroker over 400 cubes and under 430 cubes. Plan on going with a built 700r4 with at least a 3200 stall and nothing more than around 3.73s or 3.90 gear.
Should I build the L98, go with an LSx like a 6 ltr, or build an older sb? If I go with the L98 or LS engine am I better off to carb it?
working speedometer and cruise is important to me.
Any thoughts? I would love to do this for my Dad, any help would be appreciated.
10-21-2010, 01:19 AM
the silence is deafening!
10-21-2010, 10:44 AM
Low 12's will not take a ton of motor to achieve. I'd use the stock block and turn it into a 383. Low buck SCAT bottom end with Hyper pistons. Spend your money on good heads (AFR 195 Eliminators or similar). You will dump a ton of money into refurbishing all off the suspension components, all of the hard lines (fuel and brakes) and the interior. The motor will be the cheap, easy part!! :)
10-21-2010, 06:03 PM
Thanks for the input. I was reading about the vortec heads and patriots. How close to those you mentioned would the vortec heads be? I'm figuring that to follow your plan I will need a much better intake and bigger injectors. I don't know if I will need to do a computer swap or what component to go with. Right now it probably still has a chip in it but I can't imagine how it could compensate for the changes, especially if I add a decent cam (and vaccumm reservoir if needed) and headers. I don't even know what headers are available to me.
The hard lines and suspension are things I was counting on. Cost is a factor but at least it's not complicated.
10-22-2010, 06:45 AM
Your 89 computer (MAF) would be fine...if you can tune it yourself. However, the stock intake system will be a huge restriction. My car was well into the 11's with a miniram setup on a stock 1990 computer (reprogrammed). For a cheap conversion, look into converting an LT1 intake or shop around for a used miniram or a Stealth Ram. At the 450HP mark, the stock injectors wont cut it. The carb route will be much cheaper, but not emissions legal.
Stock vortec's wont get you there. Vortec's with some porting and spring upgrades would. I can't comment on the Patriot heads because I have never used them or seen them on a car at the track.
10-22-2010, 08:28 AM
Check the LTx/LSx section of TGO
Stock LS1/4L60E/T56 dropouts take a 3rd gen to mid/low 12's consistently. With your high mile/year usage, Id assume youd expect a high fuel economy which a SBC/LT1 will not allow for. Cruise is covered in detail as well
10-22-2010, 11:00 PM
Pancherj, I figured on the intake upgrades but wasn't sure the best way to go. Emissions schmemissions... I won't be worryin about no stinkin missions :) As far as heads it is probably between patriots and trick flows. I did see some good prices on 220 , 64 cc dart heads though. I just don't know if they will go on an L98 or it's any difference from an earlier chevy sb?
Pocket, Is there alot that needs to be converted over to go LSx in a third gen?
10-22-2010, 11:01 PM
Oh btw, I GOT THE CAR!!! WILL POST PICS TO PROFILE SOON.
10-23-2010, 08:22 AM
Read the sticky on TGO. It covers all the necessities in detail
10-24-2010, 10:36 PM
I don't know what TGO is.
10-25-2010, 07:52 AM
TGO > LS1tech for real info