OK, I see your point - the engine alone is probably worth it
Worst thing down around Anchorage/Mat-Su was the ice which is a lot worse than snow. I drove school bus at Chugiak for a year and never had any trouble even in fairly deep snow even with bias highway tires. Ice was sometimes bad, though.
What kind of rear suspension does the C-70 have? A lot of those HD trucks have the walking beam suspension (either one pair of springs or four rubber pads) so you pretty much have to just find another rear axle/springs to convert to single axle. In fact I've known guys that found it easier to just cut the frame and weld in another rear frame/axle rather than mess with all the brackets.
At least you shouldn't have to lift it
