so i just go a 5.7 z28 tpi, it has headers, shift kit, an new drag radials, but it hit a 14.6 at the track what can i put to give it some more power.

 

What gears do you have in the rear?

 

You stole the words out of my mouth, if its an original 350 car they usually had BW 9 bolts with 2.77's. If thats the case throw a 3.45 or 3.42 back there and you will notice a big difference. Other than that, the usuall, cam, port work, better heads, tune, etc etc.

 

stock gears, my friend is selling me some 3.73 but they tell they wont work the same as some 3.45, an the same guy has a lt4 hot cam for sell. what size of heads should i go with, an i thought u can tune tpi computer that well,

 

3.73's might be a little to much, 3.45's or 3.42's will work good. As far as heads, it depends on what your looking for, stock heads with some port work seem to work pretty good, as far as aftermarket goes, its endless. Your computer can be tuned just fine.

 

3.45s it is, im looking for a 13 second car with out noz ( had noz on my old iroc an mest up my engine bad) but i did hit a 13.4 with it..thanks man

 

I am doing my 89 iroc because of the same thing. Would not get out of it's own way. My problem was the gears. (2.77) I ran 14.2. You are in the ballpark. Irocz30589 is correct start with the rear gearing and move up. Suspension is very important also. (1st or 2nd mod) You want the energy you create to go through the tires to the track not into the suspension. Good luck and keep us posted.

 

13 seconds is very doable with out an power adders, mid-high 12's are also.

 

thanks guys just ordered the underdrive pully set, a mild cam, an 3.45..ill keep u guys posted of how it go's