Hello, I have an 89 IROC with a 5.7 TPI auto. I am looking to get some more performance but keep it looking as stock as possible. What would be my best way of going about this? Vortec heads and intake? Throttle body and injectors? Electronics? ?????

Thanks for any help

when you open the hood and look there is no way of knowing if your heads have been ported, cam changed, bored and stroked etc. So, have at it because there is no way of seeing that with your eyes.

I realize that you can't see any of that. I guess what I am looking for is a guideline or list of things I would need to get or do and still have an everyday driver. This car is unmolested and has 40k miles on it and want to keep it looking as stock as possible

A K&N Air Filter Is A Start

100 or 150 shot hidden nitrous system. Sticky tires.. Makes a 14 second car into a 12 second car immediately.. Perfectly safe if done correctly.

I would start with reading alot and learning. Get yourself a couple books on modding SBC's. Once you understand the fundementals of how a motor works, and what all the parts do, then you can determine ways to mod it. People in this hobby spend years researching parts combinations and researching magazines/books/websites.

It's like LeVar said ***Reading-the more you know***

I do understand how engines work. I have been a Dodge mechanic since 86. Just haven't done much with Chevys. I inherited this car and I want it to look stock but have more go

Tearing into a stock tpi engine is a wallet/heartbreaking ordeal. Even more so if you din't want to change how it looks. Every part of the induction is a serious restriction. Changing heads/cam requires cimouter tuning to make it run right.

Best mods ever:

Sticky tires(245/50/16 drag radials)
100 shot of nitrous
Better torque converter 2600rpm works good for TPI
TransGo Shift kit and an additional trans cooler help logevity also.

These are pretty stealhy and will let you keep uo with modern muscle. Especially from 0-60.. 15lb nitrous bottle lasts a long time with just a 100 shot. Power jumps from 245hp/340tq to 345hp/500lbft tq. No additional tuning needed. Stock timing is probably safe for 100/150 shot, same for stock sparkplugs. You can hide an aftermarket ignition box. Those help light the fire/idle/driving in general. Adjustable fuel pressure regulator can help fine tune an engine.

Exhaust mods will help after that. And that is enough power to possibly hurt the rear axle. Get a diff cover that strengthens the rear axle.

fundamentals are the same so do what you've done since 1986

the difference is for a gen 1 SBC your wallet won't need to open as wide.

Heck, you'll probably find 20 SBC parts on craigslist for every 1 Mopar, maybe more. The same with Ebay

seriously

price something as simple as an exhaust.

look at prices for performance mods on the old small block mopars; it's nuts.

i have been tinkering with the same idea on my 89 GTA with 21,xxx miles...I want it to be a little faster but not insanely fast...
everyone knows that for more power, you need more fuel/air into the engine and better flow of the exhaust out of the egine...
with that being said, i would look into porting the stock intake, plenum, runners and heads...although changing the cam wouldnt be noticed visually, it may be noticed depending on the type you get when it lopes at idle....
you could port the stock TB but you could keep it stock looking with a performance one, same with the MAF and injectors. A K/N filter, headers and a nice 3" catback exhaust should be more than enough to wake up a TPI. If you have enough $, a shift kit would be nice too. Finally, a good solid tune up including measuring fuel pressure is always good...Don't get Flowmaster mufflers, please!

A properly tuned L98 runs neck n neck with modern minivans.. So I can see the apeal to mod it a little.

My methods don't harm the driveability of a bone stock car. A lot of "bolt on" mods turn into headaches, a poorly running car, and sometimes.. Improved performance.



Goodluck!