What gear ratio is this?

[RShaips]

I bought a rear and front axle assembly from a guy and it was supposed to be from a 79 1/2 ton with 3.73 gears. I checked the ratio by spinning one tire one revolution and times it by 2 and the front and back came out as 3.73, at least that's what I thought! Well I take the rear apart and the ring gear is stamped 10.34. And i counted them and that's what it is. 3.40 gears? I have heard of 3.42 but 3.40?

[69CSTDawg]

its most likely 3.42

[rayfinseats]

10 34 is 3.2. You sure you got the right numbers off the ring gear? Put a mark on the tire and count how many times the pinion turns in one revolution of tire. What's this times two stuff for???? I have 2.73's in my 83. Which rear end is it? 10-bolt? Dana 60? 14 bolt?

3.4 what the F was I thinking?

[argonaut]

34 teeth on the ring / 10 teeth on the pinion = 3.4:1 ratio

[68chevyfuelie]

12 bolt chevy rears were a 3.40 ratio, they didn't offer a 3.42 12 bolt ratio.