318 CID Edelbrock 4 bbl Hot Start Issue

'72 Dodge Dart Swinger #'s matching 318 factory intake with Edelbrock 4 bbl (sorry, not sure specific model number, I did not install). Using a MOPAR 340 4 bbl air cleaner.

Cold start, first start of the day, two pumps, starts right up. Runs great. Run for 20+ minutes, shut it off, acts like it's flooded, lots of cranking, hold foot to floor, finally starts. This happens every time.

We've cleaned, adjusted, thought it was fuel leaking back in. Nothing helps.

I've searched the web and seen everything from insulating fuel lines to hardwood gaskets to 1" plastic spacers.

Any help would be greatly appreciated.

IMG_5828.JPG