I'm trying to identify some stuff on my 1952 GMC 9700 (Canadian 3 ton) It has the GMC built 248, and I'm not sure on what the transmission or axles are. It has a vacuum operated 2 speed rear. All I've managed to find is a cast number "19750" above it is a "M" with a square around it, and that the shifter arm is a 25397. Front axle doesn't seem to have much to identify it, but from reading Griggs disc brake post it could be a Clark F466? never seen any info on those. Bolt pattern on both axles is the big 5 pattern, 5 on 8" with a hub center of 6". Any ideas on where to look?