Just got my 351C 2V Ford Power Train Headers in. They fit like glove but won't mount up. In my '73 fast back they had a one year only calm system motor mount. I had to smash up my last one to make it over the clam. They hit on the driver side, rear, outer corner of the clam. I am not about to do that with a $1000 dollar ceramic coated headers. I have included pictures. Has ANYONE order a pair of these for a '73 and they fit?