John, the APC-guess is so close that I have to give you credit for it. Even if this particular engine wasn´t used in an APC, I assume it could have been.
When I bought the engine at a military surplus-centre, the manager told me it had been used as a starter for a diesel-engine in a tank.
I was especially happy because of the brand-new -67 302 crank and the very rare aluminum waterpump.
It also had an odd bolt-on extension for the fuelpump that moved the pump out/down 1 to 2 inches. The Holley-carb in this pic has the bowl on top of it. It´s a Holley CENTRI-VAC Governor, list # 2094-1
