Continuing on with the temperature of the engine, I found that my truck did not get warm. I confirmed that there was no thermostat in it. With a new thermostat, the temp comes up rather quickly (we are talking Florida, summer) and stops at 180. It never goes above that, even in a parade. These engines will suffer from not getting hot enough to burn off the moisture in the engine.
Now I will say that my truck has a new three core section in the original radiator. No sludge or restriction. I have also read that an engine can actually overheat with no thermostat because the coolant goes so quickly through the core that it doesn't have time to have the heat extracted. Don't know if that is an urban legend of factual.
The one thing that I always refer back to is that these trucks ran well when new. Bringing it back to original spec usually just works.
About the valve seals, I think that Kaiser fixed the leaky seals in tha 1969 trucks; or maybe they were replaced in the motor pool. If there is good compression, that's a start (and a good sign to me). As long as the valve guide is not hogged out, you may be able to replace the seals without pulling the head. That is always a BIG plus.