fuel return line question?

I have a 86 cj7 with a 258 and a Weber carb on it. when it had the stock carb on it I had a problem with it starting after it sat for about 2- 4 hour. I had to prime the carb with gas and it would start right up and run fine. I figured it was draining the gas out of the fuel filter through the return line so I put on a filter with no return fitting on it and plugged the return line and the problem never happened again. now here is the question should I be running the return line with the weber carb? I put a fuel pressure gauge on the fuel line and I am getting 5.5 psi and weber says max is 3.5 so I have a fuel pressure regulator coming at the auto parts store on Tuesday. if I hook the return line back up will it drop the fuel pressure? thanks carmine