People usually think that my Aurora is a bigger car than the Bonneville is, but the opposite is actually the truth. It'* the shape of the Aurora that makes it look bigger, but the Bonneville is actually slightly larger than the Aurora is!
In this picture in a front shot, the Aurora does look slightly larger than the Bonneville
in this view you can see that the Bonneville is actually 3-4 inches longer. The Bonn is has its rear tire against a cement parking barrier while the Aurora is even an inch from the barrier for comparision.
So is it safe to say that the H body may just be a longer version of the G body that Oldsmobile/Buick uses?