C2/C3 differential differences

[Geary T.]

I have a 63 (CF 12 2 63) differential that I want to use a 78 differential cover on. I know the spring width/pad, mounting bolts and spring retainer plate are different. Are there any other differences that would prevent me from making this swap. The 63 differential cover has 2 of the mounting threaded bosses broken.

[Joe L.]

Re: C2/C3 differential differences

I have a 63 (CF 12 2 63) differential that I want to use a 78 differential cover on. I know the spring width/pad, mounting bolts and spring retainer plate are different. Are there any other differences that would prevent me from making this swap. The 63 differential cover has 2 of the mounting threaded bosses broken.

Geary------


The 1978 cover, GM #464909 (cast 464910) will SERVICE the 1963 application IF the 7/16" spring retainer bolts, GM #457977 retainer plate AND 2 GM #459032 spacers are also used. All are discontinued but available in reproduction.

[Dick W.]

Re: C2/C3 differential differences

Correct me if I am wrong, but I seem to remember that the pinion shaft diameter of the '63 was smaller..

[Joe L.]

Re: C2/C3 differential differences

Correct me if I am wrong, but I seem to remember that the pinion shaft diameter of the '63 was smaller..

Dick------


Yes, if you are referring to the differential gear pinion shaft, the 1963 was GM #3830742 and was 23/32" OD. The 1965-79 shaft, GM #9776894, was 3/4" OD.