Does anyone know the size of thread for the feed line? I took the rail to a speed shop and they cannot figure what size it is. Also if it is -an or pipe thread? Thanks in advance.

 

It's one of those -an fittings. Not sure what size. All I know is that the 3/8"-1/8" adapter that came with my autometer fuel gauge doesn't go in there. It's just a hair too small. Sorry not very much help, but I CAN tell you that it's not a standard pipe thread.

 

The large ports at the ends of the rail are 9/16-18. You can get standard -6 or -8 adapters from Earls, Goodridge, Aeroquip, etc. These are straight threads, not pipe threads. You have to use a crush washer or o-ring. The small port on the top is 1/8 NPT (pipe thread).

Tyler