I would temporarily stick a cheap napa electric fuel pump back at your gas tank and see if the problem goes away. Sounds like your fuel line is heating up and turning the gas to vapor and your mechanical fuel pump can't suck vapor. Even with the wrap on your fuel line will heat up. It will just take longer. If you wrap the line with pipe foam insulation and then use the wrap you should be in better shape.

I had that problem with a Trans Am and could not start the car easily until after it cooled down. Both my street driven mopars have electric pumps and I don't have any hard starting or driving issues.

A moparts member named Challenger1 I think, has had real good luck running mechanical pumps. He runs the stock mopar pumps that have a return line at the pump to return fuel to the fuel tank. That way the fuel doesn't get a chance to heat up in the line because it's always moving.