A very wise father of a friend, who still had his original '64 GTO and was a die-hard "car guy", cautioned me that if I just rebuilt the heads and slapped them back on a tired motor, I could actually cause more problems.
One of those engine myths that keep on going.
About the only problem that can be introduced is debris in the bores and subsequent scoring of the walls, and that's up to the mechanic to prevent. The rings won't know the difference in pressure as they are subjected to a very wide range of pressure daily. If a slight increase in cylinder pressure could somehow damage the rings, just recurving the distributor would cause problems.
A proper leak-down test on the engine before doing any work would be a good investment so you know what needs to be addressed.
