i was wondering if a frame from a 1967 Pontiac Tempest would be the same frame as the frame in my 1967 chevelle. the frame in my chevelle is pretty well shot & would be interested in swapping it out. i'm sure buicks were the same but don't know about pontiac although i think GTO is the same. thanks Rod

Pretty sure the BOP's are a little more than 3 inches longer than the Chevelles. It is all between the last 2 body mounts. You can cut out a small piece and reweld.

That's true the BOP's are roughly 3 1/4" longer between the rear two body mounts give or take an 1/8". I did the same thing swapped out the frame under my 67 Chevelle. I was not able to locate a Chevelle frame, but I did locate a primo frame under a 67 Buick GS that someone cut the roof off the car and stripped pretty much everything else off the car. The GS frames are the boxed frames same as the convertibles and El Caminos. I used the old frame for the measurement differences and cut out the difference and welded it back together. Everything else is the same.