71C10 just stops running

[71C10daily]

Hello all, Has anyone else had this problem ? I have a 71 c10 with a 350 zz4 crate motor with HEI distributor. It would not start one morning , found it had no spark - I replaced the coil, distributor cap, rotor, ignition module, wiring harness from coil to module, plugs and wires. Now it will run for about 5 minutes and just stop , sometimes it will start right up sometimes it takes numerous trys but will just stop again as if you turned the engine off. I am stumped and hoping someone else has had this problem . what do I check or replace next?