Fenton intake and Fenton headers combination needs no adaptations.

I had to grind the Fenton headers and the Offenhauser intake (used in combination).

Fenton headers need to have no plugs welded; however, there is a hole in each header which needs to be plugged if you will not be using exhaust gas to heat the intake (pipe plugs work).

Your next question is if/how the intake needs/gets heated. Those two topics result in confusing and interesting discussions/opinions/mythologies (similar to "is there a god" and "what is the one and true religion").