Does your exhuast heat riser valve work?
The reason I ask is because it can allow for raw gas to make it to the cylinders without vaporizing.
Check your oil. It might be dilluted with gasolene, which will cause the engine to run hot, If the oil is dilluted, check you oil level. If the level is high start with the fuel pump to see if it is leaking into the block, if it is within range of the level marks, then smell it to see if it smells gassy. diluted oil cuts out the lubricating qualities of the oil and actually can act like a solvent. Not having lubrication in your piston rings and bearings can make an engine very hot.
in another instance
I had one of my 216's running hot. so I pulled the carb and the metering needle was a very lean needle causing the engine to run hot, but it would not boil over.
I run zero pound caps on all of my trucks without issue(after I learned not to overfill the radiator)
