Is it possible that when i changed my rear i lost power?

i recently took the non posi rear out of my 85 z28 5 speed i dunno what gears were in there stock and put one in from a 87 firebird posi.

i was told it was 3:23 but i found out they are 2:73.

now with the old rear i used to shift at 5500 easy.

with the new rear it struggles and climbs slowly and it seems my redline is now 42 4500 rpms

could it be cause of the lowwer gears?

thanks

 

Your old gears were probably 3.23s, and that's why your car doesn't seem to rev as quick anymore..

 

You didn't loose power, but you did loose some torque multiplication. Assuming you had 3.23's before, and you now have 2.73's, you have roughly 18% less torque multiplication to get the car accellerating. If by some chance you had the 3.43's, you are now short about 26% of what you were at.

The good news is that a gear swap is easy, and pretty cheap

EDIT: The swap probably shifted you out of your powerband some too, which is why it feels like it doesn't pull as hard or long.