We want to switch our too rusty & too dented three window 1951 GMC 3/4 ton cab to a five window cab. Which years, will interchange? Will it matter if the five window comes from a Chevy & not a GMC? Our cab has the cowl vent in front of the windshield, vent windows in the doors, & push button door handles. It has louvers on the passenger side in front of the door. It does not have the small vent door in front of the driver's door. Which years fit these parameters? Did they change the mounting pattern to the frame in any years? Thanks.