I recently just bought a 1970 Cutlass S as a donor car for my 1970 Cutlass Supreme. I was wondering if the rear window, quarter windows, main windows, and the windshield all fit on the Supreme from the “S”. I don’t know if any other issues might arise from the switch like the wiring harness. Thank You.

 

Well, a cursory look at the two rooflines should tell you that the quarter windows won't work and I doubt the rear window will fit either. I am less certain about the viability of the door windows and windshield but am not terribly optimistic.

Try taking some measurements.

 

Door windows and windshield will interchange. Anything back of the doors will not.

 

Do you also know about the wiring harness? And just any other electrical or interior differences (other than badges and emblems).

 

I think the only difference in wiring is for the opera lights on the inside of the sail panels, if your car has them. I don't know if the harness is generic enough to include that wiring on all models.

 

On the interior all the door panels are different. The doors will fit but not the same pattern. As for wiring harnesses they are the same there is a pigtail for the two on the sail panels in the Supreme.

 

FY I the quarter wimdows for the supreame are the same in the like year monti carlo

 

You own both a 1970 Cutlass S and Cutlass Supreme and you have to ask if the quarter and rear windows are the same? Sorry but once you look at them, why would you even need to ask?

ASSUMING the S is a Holiday Coupe, the door and windshield glass is the same.