I put in a 1/4 return line and matching sending unit. Not to bad of a job but not that much fun. I really had to bend the hell out of it up by the motor. When I researched this it just seemed that all the performance pumps had return lines. I got some good info about the difference on the PY site.

What I didn't realize was the stock 3/8 line was not going to do it for the Q-jet small fuel bowls and the thirsty 455. I have purchased the RobbMc fuel sending unit and I still need to get the 1/2 prebent fuel line from inline tube. I could have always went with an electric pusher pump too and kept the 3/8 line.

My brother ran into this with both his cars as well. The cars would just die off in the upper RPM and not rev up any higher. He bypassed the metal line with a rubber line and resoved the issue. The rubber line has a larger inner diameter then the metal line.

My car would hit around 4800 rpm and not rev much higher.

most people are saying the gas formula today is horrible for our performace cars. It quickly evaporates in the carb and pulling the gas makes it vapor lock more easily.

The electric pusher pump sounded like a cool way to prim the carb before starting up. I guess there is a carter pump that works really good if you plane to use the mechanical pump as a primary and the electric pump as needed. Thus the mechanical pump can pull through it.