TommyK's post is on target. The mods for the Blue Thunder are easily done. I've never had a set of AFD or CHI heads so I have no first hand experience with them. However, as I understand it, the port in the AFD head is raised some amount and the Ed 351C heads are based on the Ford 351C-2V port. Edelbrock says the Air Gap will work on 2V or 4V heads. The roof of the 2V port is lower than the 4V port. So the port mis-match of the AFD heads and the Air Gap intake could be at the top and the bottom of the port. Roy may be able to bring first hand experience to the conversation since he has the AFD heads. As far as the Torquer goes, I ran them on stock displacement 351Cs that we were turning over 7000 with deep gears that worked fine on the street. With the extra displacement and the AFD heads the torque should be abundant, perhaps too much with street tires. So, bleeding off some torque at the bottom and gaining so top end power may be a good thing. A lot depends on how you want to use the car, how much RPM you want to turn, and you personal definition of streetable. The epoxy in the intake is easy to work. Getting and keeping good adhesion was always the tricky part. I've used Devcon products in the past. However, a lot of people recommend a Z-Spar product called A-788 coated with a red sealer. It is supposed to be impervious to gasoline and oil but I don't know how it reacts with alcohol. Keep us updated on the 408 build. Chuck