All the M-1x series have cast iron cases. Aluminum are M-4x and M-3x series for rear drive -- I think the M-2x is a front drive model used in some small English cars, but may be rear drive. I've seen a reference for it somewhere but can't remember where now. Air cooled points to M-3x (or T-35, the only one I know of ever designated with a "T"). For 63-65 would be a 35. I'm not positive if the M-37 is air cooled or has trans fluid cooling, I've never had the opportunity to work on one, just the 35, a couple 4x, and a few 1x. _______________________________________________ AMC-List mailing list AMC-List@xxxxxxxxxxxx http://www.amc-list.com/mailman/listinfo/amc-list or go to http://www.amc-list.com