looking to put a 6637 filter on a '68 F500, 390 with a 750CFM edelbrock.
anyone know of an adapter that would fit on the carb and turn over to the fender to install this?

 

Can't think of any at the moment. I have a feeling you're gonna have to go 100% custom and build it yourself. I bet a home-improvement store would have a PVC elbow with the correct I.D. for you to build from. I just can't think how you'd secure it to the carb. I'd be interested in seeing this when you're done with it.

How much clearance do you have to work with?