Jerry, I think there are a lot cam choices for the six, you just have to dig a little bit to find them.
As far as the LUMP ports, they do work, its been proven, but its not as easy as just bolting them in. There is a lot of shaping to do in the port and around the valve face. My dad has a Superflow bench used to check air flow on heads. We did some work on one of my 250 heads using clay. We found a small lump at the front of the port going around the head bolt boss helped a bunch on low lift flow. Even up to .500" lift the flow was better then stock. I don't have the numbers but it was quite a bit better. We added the bigger exhaust valves (1.6") I think, and ported them as well. You can really get some flow from the exhaust, they are real close to the SBC in design. After I changed the clay to epoxy, we installed it and drove for a year with a slight miss. From What we could find, the exhaust was out flowing the intake and causing a lean condition at high rpm and heavy load. No matter what I tried, I could not cure it. I reinstalled the stock head with no other change, and the problem went away.
All this tells me there is a bunch of stuff in the flow area that I don't understand. I think the real racers raise the roof of the port and add the lumps to get the short side curve up to a better angle. If you look at a stock head the floor is lower then the valve face and the air has to dip down and back up to exit in to the chamber. By rasing everything, you can eliminate the dip. Also, the removing of the bolt hole boss doesn't add much flow, it just helps in directing the air in and around the port chamber.
Read up before cutting, you might save your self so time. Check the Inliners site if you don't. they do some pretty cool stuff.
Joe
