I'll first say im not a carb guy, I've rebuilt them with success and that's about it. During my leak search, My buddy Bob Ream / Imagine Injection took my brand new Holley 3310 and milled the bowl surfaces flat on the carb body side. He said they're rarely flat, and that hidden internal leaking causes hard to diagnose problems. Tightening the 1" inlet fittings can be a challenge so, I got new gaskets and reinstalled the fittings that came with the carb which have a smaller 3/4" hex. This meant ditching the SS Tubes set up with smaller tube nuts, no big deal, I adapted out to 3/8" clampless nipples and ran fuel hose from there. Leaks gone.
