Is overspray on cylinder head ok?

Looks like a 5 year old painted it. I totally agree with the other guys, tear it down and do a complete clean up. I would also soak those push rods too and blow them out before re installing them. Like others have said it appears to be a spray can over all. Once you pull those heads check out the bore for a cross hatch pattern and check out the bearings. Be careful with cleaning those valve springs as thinner eats rubber and that's what those valve seals are made from. Good luck