I used a 302 military intake and the Fentons on my 1950 GMC 270 with H head. The Fentons I got from Patricks also required grinding inside the ports to open 2 ports up to align with GMC ports. Also had to grind on outside a couple places to get enough clearance for socket and wrenches. Back bolt is still very tight to get to. Also made some "clamps" that span intake to exhaust with clamp bolt in middle from flat stock. Saved my stock clamps in case wanted to go back stock. After seeing Buffalo manifolds wished I had gone that way myself.
