Axle Ratio identification

[jthomas]

Good morning, I bought a rear end and motor out a 1969 Stage 1 400 4speed car about 30 years ago. All of these years I thought it was a 3:64.1 ratio Posi traction.
When changing differential oil, I read the following numbers on the ring gear. 1382746. I don't remember where I read it but could this reference a 3:91 ratio?

 

[Dr. Frankenbuick]

Can you see how many turns it takes to make one revolution of the wheels?

 

[jthomas]

Good morning, I bought a rear end and motor out a 1969 Stage 1 400 4speed car about 30 years ago. All of these years I thought it was a 3:64.1 ratio Posi traction.
When changing differential oil, I read the following numbers on the ring gear. 1382746. I don't remember where I read it but could this reference a 3:91 ratio?View attachment 12906

Thanks for the reply. Visiting family in another city. Will when I return.

 

[Dr. Frankenbuick]

Divide that number by two to get the ratio if it an open rear.

 

[jthomas]

Thanks for the reply. Visiting family in another city. Will when I return.

It's posi (limited slip)

 

[LARRY70GS]

On the Ring gear, there are 2 numbers after the part number. Divide the smaller number into the larger number and that gives you the ratio.


45/11 = 4.10

 

[jthomas]

On the Ring gear, there are 2 numbers after the part number. Divide the smaller number into the larger number and that gives you the ratio.
View attachment 12908

45/11 = 4.10

Thanks!