Is there a positive sure fire way to clean out the water ports in the heads and block to insure that there is absolutely no blockage? Without rebuilding the whole engine?
Check your thermostat, I've seen new ones that didn't work, especially the cheap ones. You can put the thermostat in a pot of water on a stove it should start to open before the water starts to boil and it should be fully open by the time the water has some bubbles forming.
I had the same problem with my comet, sitting in the driveway it would hit 200 and puke all over the without driving. I replaced the thermostat with a 160 one and new water pump but it didn't work. I ended up getting a new radiator off eBay with 1" tubes for under $200 and now it runs 170 on a 90 degree day hot rodding all over the city!
