So, what would cause a rochester 2g to be running "pretty good" for the last 2-3 days in test driving and then yesterday all of a sudden flood with gas coming out the top? (Note: carb is a late 70's chevy 2GC model which has sat on my shelf for a while and has recently been installed on engine. Rebuild history unknown) 1) The only thing i did different yesterday was to run a pcv line, from the valve cover to this port here, port "A" , whereas previously it was capped: i'm not sure exactly what this port is for or if it is even manifold vacuum, but it seemed right...... 2) i took the top off and the float does NOT seem to be leaking and there didn't seem to be any trash in the needle+seat area. i haven't confirmed if the float settings are correct, but based upon initial observation, they seem ok. Plus, if they weren't this doesn't explain it running good for the past few days----i test drove many miles. 3) Not exactly sure what the fuel pressure is, BUT this particular fuel pump is specified to deliver 4-6 lbs., and, according to the gm service manuals, these later 70's chevy 2G carbs are calibrated to take 7 to 9lbs! Also, if pressure was too high, wouldn't it have flooded right from the start? So, my hunch is high pressure is not the problem. i will install a gauge if necessary though. 4) i am running an inline 40 micron filter (the big blue thing). Is this enough? i cannot run the stock inside filter because the A/N inlet fitting won't allow this. Any ideas?