[427sharpe]

Wilf, in 68 FoMoCo still used the thermactor exhaust system, which means you can grind away the entire hump as long as the head has not been drilled by the factory (a hole at one end for the smog system hook up). Just grind away the hump and blend it into the floor of the port, than match the edges of the port to your gasket and blend it back about a half inch or so---sorry, 6.5 mm! If the head has been drilled, you can still flow the port, and if you hit the thermactor (smog) hole, just fill it with hi-temp motor epoxy and blend into the port. You really dont need to go crazy, just use common sense and make the EXHAUST port nice and smooth, with as little obstruction as possible. Oh, and port match the intake too (match the port to the gasket) ! Hope this helps!