Hot engine troubles

[Second Series]

This is a ‘47 Chevy 2nd series with a ’54 235, SM420, and 3.73 diff. I have a few issues to work out. It is hard to start after it has run awhile. If I drive somewhere and shut it off. If I don’t touch the gas pedal, I can tap the floor starter and it starts right up, but if I even look at the gas pedal it won’t start. I had the carb rebuilt awhile back, but that didn’t affect the hot start issue. I have been reading about similar problems, and realized that I may not have the Ballast resistor bypass so I’ll try that unless anyone has any ideas what else I could check.
If I drive around awhile and stop/start it a few times the engine sounds like a popcorn popper. The engine was originally solid lifters, but it now has hydraulic lifters/camshaft. This is the second engine I’ve had installed and the camshaft and hydraulic lifters came from the first engine. When the first engine was running, I abused the lifters by not adjusting the rocker arms after replacing the head. I replaced a couple bent pushrods and some lifters in engine number one. (That engine was done when a valve broke off.) I found a replacement engine and the mechanic found a crack in the cam gear, so he took the camshaft and lifters from my first engine. He mentioned that some of the lifters looked partially collapsed, but since he was out in the boonies and didn’t want to drive to town for new lifters. The engine ran fine for a while, just rattled a bit. After a few years, I had a mechanic adjust the rockers and it sounded better, but the popping when hot started. He suggested a bent distributor shaft, so I replaced it with no change. My suspicion is that there is a collapsed lifter that when the oil gets hot, that lifter expands causing a valve to not seat and I get to hear that cylinder firing. The only way I’ll know is if I pull out the lifters and check. What else do you think could cause this popping when hot issue?