Are all g-body frames the same?

I have an 1987 olds cutlass supreme and was just wondering if the frame from say a g-body monte carlo or any other g-body is the same -- length , body mount location, etc..

82-87 models should be virtually identical. The 81 is a half metric/half SAE car (even though the body looks the same), so many components attached to a rolling chassis will be different (brake rotors and wheel bearings for sure just to name two).