Need rotary guru help

[IH8DSM]

Ok the truck is a 74 repu with a 13b, as of right now its got a holley carb, a header and a rebuilt motor. The motor is street ported and made with atkins springs/seals and fel pro gaskets except for the oil control rings.

Heres the problem, it starts, runs, drives, idles with no problems but once its warmed up and you turn it off or stall it, then thats the end of it. it wont start up again till its cooled down. After its cooled down it will start and run again till its warmed up again. We're clueless at this point we've tried three different carbs ( niki, side draft, and now the holley) two completely different motors (had a fresh rebuilt one in there previously did the same thing) 3 different starters, different distributor, different igniters. Battery is good, alt is good. Used seperate parts for both motors similar problem. New fuel pump, good fuel pressure. Maybe 200 miles since rebuild, everything in side checked out fine.

So at this point getting really frustrated, So any ideas would be helpful.