Hi Frank, I thought I answered your question before. If you were fortunate enough to have a set of headers with consistent flange ears, your method would work just fine. However, my reproduction fentons had flange ears that didn't match the intake ears, and each to a different degree. For example, the front flange of the front header was off by about 5/16" on one side and less on the other, while the inside flange of the same header was a match on one side and off by 3/16" on the other. The rear header was just as inconsistent. I mated them with my stock intake and did all the grinding on the headers and none on the intake. At least it was just extra material. It also helps enormously to do it on a bench with a mock up head if the engine is not out of the truck and on a stand.
