Anyone know if you can take a frame from an Ext. Cab short box and put a Quad cab short box on it?

C.

 

sounds like a good idea but you would probably be better off buying a quad cab

 

I had a club cab and now have a quad cab, the dealer told me (and of course the info maybe incorrect) they have the same frame but the club cab's cab is 8 inches shorter and the bed is 8 inches longer than the cab and bed of the quad cab.....they have the same frame and wheel base is the same 131.1 inches....you might need to mod some mounting hardware but it seems this swap would be possible

 

You'd have an 8" gap between your cab and bed, if you wanted the wheel wells and the tires to line up right. If that's what you're going for, then bully for ya.