It may not look like it but a whole lot of work went into that. The tube frame 1200's have the motor set back that far as well...........obviously makes a huge difference. Think about all the little things involved in doing this; shorter drive shaft, repositioned shifter, wire loom changes, cross-member, relocated radiator , hoese and a whole host of minor jobs.
This is a pretty neat garage built mod, I'm sure your Dad had great fun with it.

Tom