i have a 91 z with a 350 and i run about a 14.4 at the track. my question is that if i put a set of 3.73 in there how much would it improve my times, also what gears come stock?

 

stick or auto?

 

auto

 

Was the auto or stick question really needed?

3.73 might give you .05 you already have 3.23 is your rear is a stock 350 setup.

 

3.73's won't help much if any. The stock TPI drags the engine down too much above 4500 or so rpm.

 

i thought 2.73's came stock too on third gens cause thats what i have. and i heard like at 4500-4800 rpms, the motor just wont pull somethin like the runners are too short.

 

2.73's did come stock in RS's. Thats what I'm taking out of my car Monday or Tuesday (got a 3.70 9-bolt sittin at work waitin to be put in.)

 

My auto 91 Firebird Formula with the 350 and WS6 handling package gave me a 3.23 gear. I understand the stick ones were 3.42.

Stock TPI will bog down at 4500 + rpm so I would go with a 3.73 but that is because I will be making mods in the future which I did.

 

runners are too long for high rpm. shorter the distance to the valves=more hp. long runners build tourqe.