I’ve owned a ’49 Chevy 1 ton for about a year. Done lots to it and drive it once a week. Has a ’55 235. It warms up slow and keeps warming up until it peaks at 210. Takes about an hour during summer to get that hot.

Figured I’d change the thermostat and flush the system. Found out it doesn’t have a thermostat, probably because the engine is so clogged with gunk that it needs heavy coolant flow. Pulled block drain plug and it is so backed up with gunk that it won’t drain. Stuck in screwdriver to unclog it, didn’t drain.

What would be your advice? Does reverse flushing like the manual describe work? Are flushing guns available at auto parts stores? Any good chemicals for this procedure?

Frank
1949 Chevy 3800
1929 Chevy International