Thank you guys! I will move the filter to the pressure side of the fuel line. Forgive me, what is an EVAP system? Emissions related? the Carter carb does not have a bowl vent like some of the earlier ones did that open to the atmosphere. I had one that had a large rubber flapper valve on the right side, but got rid of it.

I am agreeing with you all that there is an evaporation issue, which is why I thought the check valve would help out a little. As in if I could keep fuel in the line up to the carb, then the bowl would be the only thing I would have to fill vs. a 5 foot line and the bowl. Hence, I think it would start sooner. Kultulz, the fuel vent line is still in place unmolested at the top of the tank. I don't get any hissing or suction when I open the gas cap like negative pressure, etc.

I guess an electric pump in line with one of the hoses near the tank would get rid of the issue.

I guess in the mean time, I could run the fuel line higher along the firewall at one point to discourage drain back to the pump/tank. I could also check to see if the accel pump will shoot fuel after a few days.

This newer "blend" of gas sucks for us carbureted guys, kind of forcing us to use a electric pump. The last time I had a carbureted car was a '79 mustang in 1992 with a Holley 600 01850-C. Not the best carb, but I didn't have this issue.