Stopleak info
 

The aluminum head on my lakester's engine has some tiny leaks in the water jacket. I'm thinking of filling the head with water that contains a stopleak product, letting it sit, then drain the solution out prior to assembling and running the engine. But do these products require an elevated temperature to seal the leaks?

Jack,on any new builds I drop a couple of the AC Delco stop leak pellets in the radiator.Tom