Vapor lock?

Joel Chapman said
So I have a 71 Dodge Dart with a 360 engine/570 street avenger carb/1/2” spacer/Holley mechanical pump. I have a rubber fuel line running in the similar fashion that the stock line went. After I installed the headers I started having starting troubles when the engine is up to operating temperature. It cranks and cranks but is acting like it getting no spark. Some times it responds well to putting the pedal partially down other times not so much. Am I experiencing vapor lock? Should I reroute the fuel line? Just trying to figure out where to start looking to get it to start more consistently. It will eventually start after I play with it for a little bit which makes me think vapor lock, but I’m not Sure.

Shouldn't matter if the fuel line and hose is in/routed the same as factory. It's a float or heat soak at the carb.. perhaps.
Heat temp does it run at sitting at idle in heat and cruising down the hwy?
Engine may be heat soaking/temp rise an excessive amount after shut down and maybe an increase in cooling capacity could be the cure... but things like and initial timing increase can help.
Maybe fuel is being pushed , look down the carb after shut down for dripping fuel.
Just start with the easy and go from there