I Have an 89 Iroc_Z, 305 TPI It was 60,000 Miles on it, I just put a 3 Inch exhaust X pipe with Dual Exhaust and Flowmasters. I was wondering what else I could put into it to make It have more than 235 HP. I heard that a good aftermarket performance chip would add alot of HP??? Would it??

 

No, it won't.

Headers, cam, larger intake valves and ported heads, replace all of the TPI hardware (base, runners, plenum - Holley/Weiand Stealth Ram replaces all 3).

Then, reprogram the computer to accommodate those things.

Even easier - a 4" bore kit. Really makes all of the things above work even better.