Stuck in traffic 340 got up to 220

Ignition timing is a big deal too.
If you don't start the combustion process soon enough, then the mixture keeps on burning as the piston is heading for the bottom. This puts extra heat into the cylinder walls and into the cooling system.
Under no-load or low-load situations below say 3000 rpm, your engine might be wanting 45/50/55 or more degrees of lead, to get the job done. So for sure, you need a working vacuum advance system.