Engine starts fine - drives fine for 5 minutes - then stalls at low rpm - won’t start again (battery and starter are fine, just won’t ignite) - after 10 minutes it starts fine and won’t do it again for days. Then does it all over again exactly the same. I have changes plugs, wires, dist cap & rotor, PCV valve, coil, camshaft positioning sensor - Still does it.
I am not a mechanic so bear with me but it seems as if you’ve eliminated spark so what’s left is fuel. You may have a wonky fuel pump or maybe a relay that doesn’t like heat. Just a guess though.
The V8s in these trucks of that vintage often had problems with the intake manifold belly gaskets failing.
How 'bout the crankshaft position sensor?
Other possibilities are a flaky fuel pump or the ASD relay. Both of those are related in a way.
The unknown here is what is missing when the engine will not start; fuel pressure or an ignition spark.
+1 on checking the fuel pump and fuel pressure.