Ideas on running a fuel return line
yes the car had a charcoal canister which is long gone and I understand that I can use the old feed line for a return, what I'm trying to get a grasp on is the plumbing up front to initiate the return...
That's the simplest part of the whole deal. Use one of the filters I mentioned, or a similar device. Those two Wix numbers have a dedicated return fitting WITH THE ORIFICE already in the filter. Just install the filter as close to the carb(s) as practical, 1/4" line "up" and plumb that fitting into your return tube. easy.
This constantly returns a small amount of fuel to the tank, helping to reduce heat buildup in the upcoming fuel--because it's always moving, and provides a pressure relief on shutdown. Any vapor trying to form in the output side of the pump simply builds a little pressure and forces fuel back through the orifice to the tank.
A picture that I "stole" somewhere:
http://media.photobucket.com/image/%2522vapor return%2522/h2ospout/IMG_0885.jpg
Here's an example of what is most probably a GM pump, with a vapor return off the bottom of the pump. This tube extended to the top of that big can, and had an orifice either at the top or bottom. I never figured they would work as good as one closer to the carb:
http://articles.directorym.com/Images/Image.aspx?ParagraphId=208
Another thing that is helpful IF vapor is the problem, is a rear-mount electric pump. This is because a stock up-front pump is SUCKING on the inlet line, LOWERS the line pressure, and LOWERS the boiling point. A rear "pusher" pump, keeping the entire line system under positive pressure, INCREASES the fuel boiling point.
