Classic/Antique Car Repair: overheating, timeing, rotor

Question
I have a 1949  chevy pick up truck with a small block 350 engine. It tends to overheat when waiting in traffic or slow stop and go (like when in a parade). It does not smoke however overheats to the points of loosing power. What could the possible cause be, how can I identify the problem and how can I possible fix it?

Answer
Jaime;
The first thing I would do ,is what I tell everyone and that is to take a presshure test this will show any leaks. I would also check the timeing , and you say it looses power I would check to see that the dist. is in right and that when on tdc the no1 plug should be on the no1 on the cap / rotor. if off it can cause you to over heat.