Recessed valves

If the valves have recessed, you'll need new seats installed. Any competent machine shop should be able to do this, it's a standard operation. You also need new guides, and probably new valves. In other words, you need a complete head rebuild. The heads you have now should be OK as cores, they just need everything.

What is your budget? You'll have several hundred into these heads, and new heads can be had for only a few hundred more. Or perhaps you can find a set of used heads that can be run as-is for a few hundred less.