Wow, that is a nice compact package. I assume the stock injector system is being used.
I would get a fuel pressure guage. The kind that has a long enough hose to fasten to the windshield wiper to go for a test drive. If you could find out what pressure the system runs at. What is the pressure when the key is first turned on. What happens when you start cranking, and where does it end up at idle.
The FPR should be set to rise one pound of fuel pressure for each pound of boost. It may rise higher than that if they are using fuel pressure to up the flow through stock injectors.
I don't know how your truck it geared, but I would want to know if the fuel pressure holds up through a wide open throttle shift, from second to third. It would be best if someone could ride along to watch the guage.
That is about the only way to know for sure if the fuel pump is keeping up with the demand. You could also do this on a chassis dyno.
Meanwhile, try to keep track of engine temp and frequency of the hard start, relative to engine temp when shutting the truck off.
If you come off of highway speed or from a recent "beating", the engine needs some time to get the heat transferred to the radiator and out. If it is turned off shortly after highspeed use, it would be interesting to know if that is more of a problem starting after a few minutes.
Typically, vapor lock takes a few minutes after turning it off to become a problem. If you can turn it off and immediatly start it back up without a problem, but it you wait fifteen minutes or so, and it won't start, that's likely vapor lock.
I use ty raps to hold the guage to the windshield wiper arm.
