Engine Won't Start when Hot. Help!

[Radiatta_71]

Here is the situation...

Starts fine when cold but after it warms up it acts as though the battery is dead.

'72 blazer 350 with newly installed HEI (although did the same thing with points but only occasionly) headers. Has a new battery, starter, Starter solenoid, plugs, cap and rotor, spark plug wires and a new cable going to the starter from the battery.

I also added a shroud to the starter sol. thinking it was heat related.

Could the timing cause this? I know the timing isn't perfect but I adjusted it a little and no effect on starting.

I am stumped on this... what else would be heat related?

Thanks all!