I am trying to figure out what the ratio is on my '72. It was an SS with the 300 hp 350, and as far as i know it is the origional rearend, it is a 10 bolt non-posi. I cannot find or makeout any of the numbers on the tube so i cannot just look up the code. I did however try marking the axle and counting rotations and i got almost exactly one and a half rotations on the axel for one full spin of the wheel. Can anyone tell me what ratio that works out to be? Thanks.

with a non posi i think you double the # of turns, so its somewhere around 3.00, if you go to a list of avalable gears for that year you would probably come up with something in the 2.9x to 3.1x range(like a 3.08 i would guess)

I looked it up and it would be a 3.08 (assuming it IS the origional). Now i just need to decide what i want to go with. Thanks a lot for the help.

3.08 is a good all around gear for a driver.