1987 Chevy Chevelle loading up and missing

would runnig hot cause chevy 350 to load up and miss when driving,(sounds like popcorn machine)normally runs at 197-203 but it was at 234 when I started driving it, so I shut it off and parked it before it made anything worse, this is in a street rod, it was running fine 2 days ago, the only thing I did differant was I let it sit while it was running and the choke did not release so it ran at a higher rpm while idling for about 10 mins and engine got up to 234

Kelly