Hey Guys, I am trying to determine what the correct Carter mechanical fuel pump is for my 1967 Pontiac Firebird 400 /4-speed. Please note, FWIW, I suspect that I have a 67' 400 from a GTO transplanted in my Firebird.

I am having fuel delivery problems and working my way through the fuel system from rebuilt carb. I searched online and its appears that M4522, M4684 and M4523 could fit - but the vehicle fitment specs conflict across Summit, etc.

I do not care about keeping car 100% stock - just want a high quality pump that will not require adjustments. Thanks in advance.