I’m disassembling my truck (1955 2nd 3100) for rebuilding/restoration. It hasn’t run for about 20 years. It’s a modified truck with a hopped up mid 1960s 327, Saginaw 3-spd, and an early ‘60s rear axle. Thought that I’d Jack it up, spin the wheel and see what the axle gear ratio is. The axle has a posi tag on it but upon spinning the wheel, it’s not a posi…bummer.
Here are the numbers on the rear axle. L143, 3725899, GM34
3725899 = casting number, used from ‘55 to ‘64.
L143 = date cast, L - December, 14 - 14th, 3 - 1963
I’ve read that typical ratios for this axle were 3:70 or 3:36.
I was expecting 3:70 or 3:36 but the result was 1 rotation of the wheel/tire equaled 1 & 5/8 rotation of the pinion. A ratio of 1.625 ??? Can that be???
I was certain that I was doing this wrong, so read some tech articles, YouTube videos and then spun the wheel again, 4 more times. Same results. Am I doing this correctly?
-Mike
Last edited by Mike34; 06/12/2023 2:41 AM.
