I got the drive train installed and I thought I'd update my results. The rear end and drive shaft (from the 8 1/2") fit just fine with problems. The 318 had the new style aluminum water pump and the radiator (which I'm sure came another car) lower outlet was on the same side. The only real modification was the motor mounts. The left (drivers) side just needed about 3 washers, and for the right I just made a spacer with a piece of black pipe and used a longer bolt.
I've attached a pictures of my motor installed.