Installed my 455 with the 700R4 in my 71' Skylark last night. Problem arose as i tried to install the headers. The top of the flange where the collector bolts on hits the crossmember and i cannot get the header tight against the head to put front bolts in. I have the long tube headers from Mike. Question? will it cause any negative effects if i cut 3" out of the header or should i add and additional 6" piece. I felt it would be easier for me to do one of these than to try and remodel a crossmember. Thanks for you input here.