[mr0077]

Silk, the phenolic spacer has very good insulating properties...it conducts less heat from the manifold to the carburetor, so less liklihood of a boilover during the shut-down heat soak period. I have a similar problem, I just hold the throttle wide open during hot starts, it clears the rich condition pretty quickly.

Also, regarding the return line...with a mechanical pump it seems that you could run from the carb tee to the suction side of the fuel pump and keep all of the line in the engine bay rather than run it all the way back to the tank, just to simplify things...that way, the excess fuel could bleed back on the the tank supply side of the pump...it would be best to use small diameter steel line where possible for safety reasons, and be careful how you route it...maybe just parallel the supply line from the pump to the carb?