1994 dodge ram B350 van starting problems

I have a 1994 dodge ram B350 van (5.9L V8) and it starts just fine when i first start it but when i drive it enough for the engine to get to normal temp. and turn it off it will not restart but most of the time if this happens it has a full day to cool off before i try to start it agian. I just replaced the battery,starter, and the crank sensor in it, What could be causing this? Anybody else have this problem?

All help is greatly appreciated!

When it doesn't restart, do you have spark and correct fuel pressure?

I had a problem with my PARK/NEUTRAL sensor on the transmission one time. There was a small oil pan leak that would get the sensor dirty and I could not start it because the van did not know if it was in PARK or NEUTRAL which are the only starting gears!

correct fuel pressure. battery charge is required for start. Does it crank at all? Or does it not crank?