Im lookin at buying a Oliver 77 gas row crop that needs a motor (there is no motor in this tractor), i wana know.. 

About what price is fair (no rust, new front tires, rear tires are good)
How hard would it be to find a motor to drop in it, running, or rebuildable with no missing parts, gas or diesel
And does anyone know if a GM (Detroit diesel) 3-53 would fit in a oliver 77?

thanks for the help!