I have used the 2" primary TTI headers in 2 builds so far, a 440 '67 Dart, and a 383 '67 Barracuda. I didn't bother reading the directions on the headers, and only after did I read they won't fit a low deck with stock port location heads. Oops.. They were MUCH tighter on the low deck, they lightly touch the bellhousing area of the block on the passenger side, and lightly touch the mini starter on the drivers, but not enough to cause any issues at all. If the Edelbrocks raised the ports at all, the fit would be MUCH improved. The only fitment issue I cannot address, is that I used a motor plate on both builds, so I don't know how fitment around stock style motor mounts would be. Good thing I prefer motor plates.