Rear end ID help.

[OldChevy61]

Found a rearend on craigslist to replace the ho in my 62. Can anybody identify these no,s before I buy. Casting is 3838227. Code is wa-10-24. There is also a gm6 on it. Any help appreciated and value if known. Thank you.

[par4tom]

3.73 posi traction, Warren plant. Pre 65 axle so I believe this is a coarse splin, not the more common 30 splines of 65-71. Check out some threads here on those...they may be tougher to find parts for. Manufactured on October 24th

[1963c-10]

Only difference in the 63-64 rear ends will be 17 spline axles vs. the later model 30 splines. All parts are still available for the rear diffs aftermarket except for the axles. I have not found a source for new 17 spline axles. Posi units still pop up from time to time. I found a NOS unit 2 years ago.

[1963c-10]

Here is a pic of the posi unit I picked up for the 17 spline axles.

Little more on the 63-64 rear ends. 63 and some early 64s had pressed on backing plates. Later 64s had bolt on backing plates. You can also remove the 17 spline gears and axles and convert to 30 spline. To my knowledge all the parts from the 63-early 80s 12 bolts will interchange (minus the 17/30 spline axles).

Be sure to get correct parts for which series carrier you have.

3 series houses 3.42 and higher gears
4 series houses 3.73 and lower

[OldChevy61]

So it is posi? The code I found said 3:73 (exc positrac) ..

[par4tom]

Here is what I have...mine says 3.73 excl??? Positraction

[1963c-10]

WA is a non posi 3.73

WC shows as the 3.73 posi code

Best thing to do is pop the rear cover and verify. That will definitely let you know posi or non posi and what gears you have. The gears are stamped on the sides. The rear end may be a 64, bt you don't know whats inside unless you pop the cover.

1st Pic for reference posi unit....in this case you see the part # 3862691 and 14-43 for the gear size. Divide 43 by 14 = 3.07 gear
2nd pic for reference non posi unit #3862525 11 41 would be 3:73

[OldChevy61]

When look at that I see 3:73 (exc positrac. ) Not sure what the exc stands for. Rear is an hour away or I would just spin it to find out. Lady already thinks she has a goldmine just because its 60,s.lol

[1963c-10]

exc = except

[OldChevy61]

I assume the posi ,both wheels will spin same direction at the same time? On the old rear I just took out only one wheel at a time would spin.

[1963c-10]

That's correct.

[OldChevy61]

Thank you. I have the owner checking it for me now. If it wasn't an hour away in beach traffic I would check myself. It has been cleaned up and painted, and wrapped in shrink wrap, so who knows,might get lucky.

[OldChevy61]

Still waiting to hear back, so whats a fair price on this rear end,assuming it is what the code says it is? And what's my chances of stumbling on a posi in the pick n pull.