Is overspray on cylinder head ok?

Good catch. Likely has hydraulic lifters in it with solid lifter valve train. That valve train came with solid lifters which were shorter in the pushrod seat area.
You know Rob, sometimes the board goes over the top with suggestions. We've all read about asking for a little more pep from a 318, and ending up with a stroked, aluminum headed blah blah blah.

But in this case, I feel that it would in fact be wise to look a little deeper. Not saying that he needs to dump a ton of $$$, just catch any catastrophic potentials. Can you imagine running that valve train?