This is for a 1965-1971 ish Quadrajet with a 7/8-20 thread.

I purchased a new fuel inlet nut/fitting from Cliff Ruggles (http://cliffshighperformance.com/). It has a half inch of thread engagement in the carb housing - which is suppose to reduce the risk of stripping the threads. It fit nicely and I was able to tighten it sufficiently to not leak. This item is also available from other sources - like http://quadrajetparts.com/.

Cliff supplied a fiber washer/gasket which i could not get to stop leaking. I replaced it with a solid aluminum washer/gasket made by Moroso. It is 1/16 inch thick. It doesn't leak. I bought it at a local speed shop.

Holley also uses 7/8-20 thread and makes 2 styles of washers/gaskets. P/N 26-102 is nylon, and P/N 108-8 is rubber coated aluminum. If you can't find the Moroso part, these should be available locally.

 

Looks like you have a bit of a vacuum leak there.

 

LOL. Sadly, this isn't the only thing I am working on.

My car had a fuel inlet fitting with a 5/16 hose barb, a section of 5/16 hose, and piece of 3/8 aluminum fuel line that was just cut off - no hose fitting.

One thing at a time.