1968 Chevy C-10 rear end

[brad4176455]

I was wondering if anyone knows of a way to figure out what gears are in the rear end of my truck. I have a 1968 Chevy C-10 longbed with a 307 and a two speed power glide. I am looking a putting a new transmission in it but i would like to know what gears i have first.

[GASWAGON]

Originally Posted by brad4176455

I was wondering if anyone knows of a way to figure out what gears are in the rear end of my truck. I have a 1968 Chevy C-10 longbed with a 307 and a two speed power glide. I am looking a putting a new transmission in it but i would like to know what gears i have first.

Welcome! Pull the cover and look for some stamped numbers on the ring gear. A example would be 41 and 10 which would translate to 4.10 ratio. Divide the smaller into the larger to find your ratio. J.

[brad4176455]

ok. thanks i will have to do that. Does anyone know what the stock rear end gearing is? Everything else on the truck is factory so i would assume that they didnt do anything to the rear end.

[GASWAGON]

Originally Posted by brad4176455

ok. thanks i will have to do that. Does anyone know what the stock rear end gearing is? Everything else on the truck is factory so i would assume that they didnt do anything to the rear end.

I think you will find 3.73 is your ratio. I believe that was the standard ratio for half ton in 67. A 4.10 ratio was a option. I am sure somone will correct me if I'm wrong.

[oldblue1968chevy]

my truck was 307 3OTT with 373 open rearend

and he^^^^ told ya how to do it right

[raycow]

As already stated, 3.73 was the most common gear. However, you can find out what is actually in there without pulling the cover.

Jack one rear wheel off the ground, put the transmission in neutral, and the parking brake off. Put matching marks on the pinion yoke and differential housing. Turn the wheel exactly TWO revolutions and count how many times the driveshaft turns, estimating any fractional turn as closely as possible. That number is your axle ratio.

If the wheel is difficult or impossible to turn, you may have posi. In that case, jack both rear wheels off the ground and turn either of them only ONE revolution. Count the driveshaft turns the same way as for an open rear.

Ray