tons! size, dash, body line, 36 has crank window, doors, headroom. thats just the main stuff. im sure mounting holes, steering colum hole and pedal holes and tons of other little things are different.
It is a for can, hell anyone knows that. I am guessing that we are talking about a Ford truck Cab. the n is right next to the b. But that is just a guess, what I want to know is does it have gang doors? Oh if my guess is correct the only thing that have in common is that both are truck cabs and both made by Ford. The '39 and '40 are pretty close but the '40 is light years away from the '36.
Besides the obviously different body lines since the cab dimensions aren't the same I would ***ume the body mounts are in different locations and the steering column placement is different. Do you have one but want the other?
Or are you asking what parts will mix and match body wise? That would be few. looks wise I like them both but on a 1/2 ton pickup favor the 40 this time.