The vast majority of those came in motor home chassis. They were all automatics, the manual trans version is not as common as the auto for that reason even though most of the non motorhome apps were manual trans equiped.

The heads flow worse than a run of the mill SB head. Chambers look sorta like a 516 BB head but with tiny valves and huge space between the valves.

I am not causing global warming, I am just trying to hold off a impending Ice Age!