Ive been trying to figure this out
ive been trying to figure out how much horsepower my car had stock from the factory

Its a 91 z28 convertible- 5speed

now edmunds.com which is usually accurate with horsepower says its 230hp
i believe that my car also has 3.08s stock

but the charts i find everywhere online says the m5 z28's that come with 3.08s have only 205hp...

I know up to 1990 the 5 speed 305's got the better cam that gave 25 extra hp

but mines a 91 so i dunno, could edmunds be wrong...

THey didnt offer g92 packages on convertibles so it cant have 3.42's in the rear

anybody actually know?

 

230 hp 300 fp torque

 

yep, right around 225. Gears don't make any difference in horsepower, only in racing

 

im aware of that i was just using it to point out that my car doesnt fit into any of the charts

 

www.thridgen.org

91 Z28
Formula
Trans Am
GTA

M5,A4

LB9 V8 9.3:1 5.0 (305)

205hp@4200 285tq@3200

TPI 3.08

if you are positive it doesn't have the G92 than that is what you have.

crawl under and spin the rear tires, count the drive shaft rotations just to check