early A-BODY 1-5/8" x 1-3/4" SMALL BLOCK STEP HEADERS

With headers I am sure it is a different story, but I thought I would mention this just the same: I run the factory stock manifolds with the TTI 2 1/2" dual exhaust system on the '65 Formula S. The instructions included the machining of the oil filter bolt head which we performed. I don't know why it was recommended for the stock manifolds using the TTI head pipes because the way the shop installed the TTI system it didn't seem necessary to me. No photos available for the moment because vehicle was stripped for body refinishing.