Filter with Return: Cure for Vaporlock?

Yes definitely a phenolic carb spacer, I put a 1/2" spacer in my buddy's 383 Dart, 800 Edelbrock carb. Could not believe the difference, the carb was hot before then after driving 20 mins the carb was cold. The heat is also blocked to the intake.
Oh heck yea! On my old Duster I could hear the fuel percolate. I luckily only needed the thick gasket Edelbrock sells.