hard start issue when hot

If you are running a ballasted ignition system, a high resistance connection there (at the resistor)could do it.
If the starter cranks slower when hot, it may be pulling all the juice out of the battery, leaving nothing for the ignition system. Multi-spark systems like 9.5 volts minimum,IIRC .Mopar boxes usually fire down to 8.5.
Next time the engine is shut off hot, jump out and remove the air cleaner assy. Hang around for 5 minutes or so and listen for fuel percolation in the intake, and watch for the vapors coming out of the air-horn.
Then pull the coil wire out of the cap, near-ground it,and crank the engine over, watching for spark. Pay attention to where the spark might go in relation to where the fuel is. Wouldnt want to hear about a fire ruining your project.