OK, based on my personal observation, the late "C" and "D" engines look pretty much similar in bricktop form. AFAIK the "C" engines have conventional recoil starters on top, the "D" engines have the "fingertip" start. The "C" engines have a pull-up choke and on-off switch in the same place the "D" engines have a push-primer and on-off switch. Of course the bearings are different and the piston has 3 rings? instead of 2 on late "D" engines.
Do the muffler plates match? Can you interchange a "C" and a "D" engine on the same magnesium/aluminum deck?
Do the muffler plates match? Can you interchange a "C" and a "D" engine on the same magnesium/aluminum deck?