i have a 90 camaro rs. it came stock with a 2.73 non posi rear. my friend sold me 3.42 gears out of his 91 firebrid which i tried to put in. i got it in but it was not properly set right, however it was driveable. i went back to him and decided to buy an entire rear end from him out of another 91 firebird that he said had the same gear ratio. we got the new rear end in and it runs fine, but for some reason the first set of gears seemed faster even while winning then my new rear feels. is it possible that the new gears are not 3.42 like the first set? is there anything i can look for that will tell me the ratio of my current gears?


also if it helps, my car originally had drums and was switched to discs with the rear end swap. i keep seeing this g92 thing around. were all disc brake cars g92 cars?

 

Just curious but when you put those 3.42's on the first time did you change the carrier?

In answer to your question about checking the gear ratio pop the cover off and it will be stamped on the edge of the ring gear or you can count teeth and divide the ring gear by the pinion gear.

I don't think disc cars are all G92, I think (Not 100%) but that is just the code for posi cars.

 

when i did it the first time i changed the carrier and the pinion.

was it that all rear disc brake posi cars were G92?

 

G80 is the RPO for posi. G92 means 350 w/ rear disks. G80 was a requirement (prerequisite) for the G92 option. In other words, you could have posi (G80) without G92, but you couldn't have G92 without G80.