my sm 465

[necromonger]

hello all,i have a Sm 465 i am putting in my 83 gmc 3\4 ton 2wd.now here is the question how can i tell what year this tranny is?

[Captkaos]

4x4 specific, visual inspection
69-78 has a 10 spline output (figure 8 mounting)
79-91 has a 32 spline output (round 6 bolt mounting)
There was a C/K (new bodystyle) 88-91 version that was the same as the 79-91, but they had aluminum top covers

[Prong]

I thought the 32 spline units didn't come along till the early/mid 80's?

[Blazin]

I thought it was with the body style change in 81. Never dug into the years for them that deep though.

[necromonger]

thank's my top cover is cast iron going to put new seals in today front and rear so the rear splines will tell me about what year.thanks a bunch.

[Captkaos]

Nope, it was 78 when it changed.

ONLY new Body style C/K's had the aluminum top...

[necromonger]

also can i run 50wt oil in this tranny with no problems?

[Captkaos]

50W gear oil yes.