I think you missed the Mark on this one, bud. #1: The first rule to gaping C3 doors is making 100% sure your body mounts are in good shape and do not need to be replaced or adjusted. #2: Start with your door shims, and get them as close as possible #3: Your gap should be the width of two paint sticks glued together as a reference before the final paint
Love your video but I had to turn it off because it was giving me anxiety lol. I may just have to take my 76 to a body shop to make sure my door spacing is set properly