Frames should be the same. The '67 may have a few different brake line clip locations since it uses a different set-up due to a dual line master cylinder. There may also be a slight difference in the bracket for the auto trans linkage if that frame had a turbo in it. '66's must have been bad at destroying frames. I had to replace mine. I used the frame from a '66 4-door. Got another one of these frames if anyone out there needs one.
I'm in the process of doing just the opposite, a '67 on a '66 frame. They should fit, but the springs will be different. Elcamino is right, '67's are unique. They're the last year Chevy made them where the bodies are interchangeable, but with subtle changes to suspension conponents. In '68, Chevy started making the frames unique to different models. Good luck.
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