Originally Posted by Louisville Joe
The comapny I work for had a few GMC C-6500 5 yd. dumps with 427's in them, backed by a 5 speed and a 2 speed rear axle. They ran very well, even pulling a backhoe on a trailer. Very thisty! It's all in how they are geared. As for the Ford GAA tank engine, I don't know too much about them, but I read where they weren't really a Ford design. They were a cut down Rolls-Royce Merlin aircraft engine.
The Ford GAA was a Ford designed V8 engine. Ford was asked by the US government to manufacture the V12 Rolls Royce Merlin engine, but instead decided to design their own engine. The confusion might be because it was the same 5.4 inch bore as the RR, but was a completely different engine. It is all aluminum with steel sleeves , gear driven dual overhead cam design. 4 valves per cylinder .THe V12 version came first therefore it is a 60 degree engine. It was only built in small numbers ,The V8 version came later known as the GAA engine. It was built in large numbers and powered many US army tanks, The GAA had 1100 cubic inches and developed 500 horsepower.