If the engine is blocked, the radiator probably is too!
Ours ran fine most of the time, except steep climbs where it would push water out the over flow and cap.
We had the radiator opened and rodded out, and got about 1.5 cups of crap out of it, just from the mechanical process! They soaked it after that.
Runs perfectly well now, even on long steep climbs in hot weather - we've since added a thermostat(160F) and temp gauge, and worst i've seen since was about 195F on a long steep climb, where I was starting to get concerns about double clutching and actually making it into FIRST gear while moving
