i have a 89 formula, 305 5 speed. i bought the car w/ a bad rear end and swap all the gears in there and the axles for a 83 camro (know nothing else about it) now the gears seem awfully tall 5th gear 60mph less then 1500 rpm. how do i find out what it is and what should i put in there?

edit...both were 10 bolt

 

Pull the cover and check the ring gear od for the stamped gear ratio. All gears have these stamped numbers, forget and about turning the wheels or dr shaft to find out the ratio.

 

i could not find any ratio's stamped on it....

edit.... looked over it again found numbers stamped but was to worn to be able to read (on the original 89 rear). won't be able to pull cover to checked 83 camro swapped gears untill monday.