[GStage1]

68 is slightly different cosmetically in the cross-member under the engine. Has to do with the "tongue" design.

All A-body models share the same frame for 2 dr coupes. All convertibles share the boxed frame from 68-72. I no longer have a picture of the 68 GS400 that I stripped for parts and sold.....but there is a difference if you know what to look for on the frame. Unless the cars is a concours show car, no one will know.