Call Barry Robotnick at Survival Motorsports. He is a master with FE fords. A real sideoiler from 66 / 67 is very pricey! I sold a couple crappy ones for 2K each. If he can prove they're from H-M, they could be almost priceless. You can still contact H-M too, they have odd ball office hours but you can reach them. A tunnel port 427 has only one purpose and that's turning high rpm! Forget about adapting it to the street! It's a race only piece, but damn I'd love to have it! Hint Hint!