I have sold it. I have a 3.42 Eaton Posi. with 31 spline axles. I was told it came out of a 1973 454 Caprice. It has a 10 bolt cover but has 12ea 1/2 inch bolts holding ring gear to carrier. The code on the axle housing is VE P 257. I can get more measurements. Does anyone recognize this?
Are you sure the axles aren't 31 spline. It should be an 8.5 10 bolt. http://www.jdrace.com/content/diff_id/10b85.php
It is larger physically than a 12 bolt chevy rear end. I measured the ring gear and it is 8 and 7/8 " outside diameter, same as a chevy 12 bolt. There are 12 bolts that connect the ring gear to the carrier. They are 1/2 " NF left hand thread. The only numbers on the ring gear are GM 41:12 1 73. I recounted the splines, I stand corrected there are 31 splines. The wheel stud bolt pattern is 5 x 5.
That is a full size car rear - 10 bolt PONTIAC looking cover (like a GTO) But bigger. The ring gear bolts are 7/16" 20 thread pitch and left hand thread bolts 1978 - 1987 they were used in Wagons and Caddy devilles etc. came in 28 spline and 31 spline These rears were the same width and would bolt right into a 73-77 A-body car. That is how much a B-body chassis got in 78-87...lol 1973-1977 A- body cars had a version of this rear too BUT they were 5 on 4.75 medium car bolt pattern.
I would think someone with a big car would want that rear. Not too many of them had a desirable gear ratio.
Yes BUT remember it is a 1978 - 1987 Big car...lol. NOT the 1971-1976 Big car. 1978 - 1996 were rear ends from A body chassis cars from 1973 1977
God, WHERE the heck did I get Monte Carlo from....LOL (READ JIM) Geez...I am OLD! Yah that will be super wide. 64" - 65" drum to drum ish Will fit all the 1971 -1976 B-body cars 4 link control arms, shocks in front of axle tubes
