Can anyone tell me about how to keep a 401 running cool. Here's my issue:
If it's not a cooling system problem (collapsing hose, spun water pump impeller, etc), it could well be not enough spark advance.
1. Suck on the hose to the distributor vacuum advance; timing should advance 15 - 20 degrees.
2. With the hose pulled off, rev the engine up to 2500 - 3000 rpm. Spark timing should advance about 15 - 20 degrees.
Retarded spark will kill power, and cause overheating and burn exhaust valves. I ruined a good engine this way, its easy to check for and eliminate.