When were the spark plugs last changed
Also spark plug wires
My '94 Ford wires lasted 18 years, or so I thought, sure ran alot better after I changed them, lol.
Heat changes resistance in spark plugs and wires, as they get older they can get above specification when hot, causing random misfires.
Other heat related misfires can be the Coil Pack, my '94 coil pack still works fine but..........doesn't mean it will last forever.