I've got a stock 305 TPI engine in my 1990 IROC-Z, it's standard and I need a suggestion. I'm deffinetly adding a Flowmaster "American Thunder" package to my car. But the engine lacks something. I need more power (and possibly torque) Idealy I'd like to get a L98 engine in it, but I also want to keep the car relitively stock. (and maybe be able to switch from mod to stock if I ever had to) Are there any suggestions on the best bolt on for the lowest money (obviously I need to spend money) but I'd like to know the best mod for the price for a 305 TPI.

 

Headers and cat-back to start. I'd suggest the Hooker cat-back, but sounds like you have your mind made up. But if you want to check out my soundclip of the Hooker, it's in my signature.

If you have an auto, some 3:42s and a higher stall TC would help a lot.

 

Iv'e heard that if you put headers on a TPI you can't go back to stock, is this true? and how much power can I expect (average of course) in getting headers? as far as the cat-back, I'm always open to suggestions but I like the "Thunder". I have a T-5 w/c, not an auto. (woulden't be caught dead with an auto in a 305)

 

cam, headers, intake, carb, highpo ignition. if money isnt that big of a concern mods are unlimited till your wallet is bone dry.

 

Why would he get a carb, when he has TPI?

Then some 3:42s would go nice.
A cam is a good mod too, but you said you didn't want to change things to much.

Headers on avg should be good for 15-20hp and a cat-back probably around 10-15.

 

Mark, Hookers did sound sweet, maybe I'll change my mind. But what about the headers, I don't want to change my engine too much, could I go back to stock If I added headers?

 

I don't see any reason why you couldn't, the only thing affected is the flow of air exiting the motor, same as if you wanted to switch back from the stock one.

Oh, and that sound clip is shifting at 4k rpms, I'll try and get some higher rpm shifting clips this weekend when I go home.

 

Allright, Headers are the way to go then.

 

Why would he get a carb, when he has TPI?


well in mhop a finely tuned carb with kick the living crap out of a tpi, tbi, or wahtever crap is on the new motors these days. why do you think dragsters and ****tttz run carbs. and i only threw that out there as an idea. not that he has to do it.

 

True, TPI isn't the best at higher rpm breathing, but he says he doesn't want to change to much, and he's just lookin for some extra power, not a 400HP monster.

 

nobody is gonna find out that you have 3.42s or 3.73s just from looking at it

 

3:42s would be the best gears to go with a near stock TPI.