Are SM465 cases interchangeable

[sqhead]

I have an 85 Chevy k10 with SM465 and was told that the countersafts came in 2 size on the input side 1.3” or 1.4” for later years. Mine is 1.4”. I’m looking to get another case to swap all my parts into and found one out if 78 k10 but don’t know if the counter shaft is different size or if it even matters if it’s just the ID of the bearing that’s different and case is the same. Are the cases and tops interchangeable for my 85 and the 78 I’m looking at. Info and knowledge needed. Thanks.

 

[PrairieDrifter]

I've never heard of any differences. I assume it would all be in the bearings. I know the round pattern 205's have a bigger input bearing.

 

[pduffyd]

Sqhead.
Check put this site for some good info on SM465.

The Novak Guide to the GM Muncie SM465 Transmission

Comprehensive guide to the GM Muncie SM465 transmission — history, identification, specifications, rebuild info, and adaptability for Jeep and GM applications.

www.novak-adapt.com