I would take the head for a valve job while you have it off. Get new valve stem seals of course. The shop has a vacuum table and can pull vacuum to see if the valves are leaking, but I'd just go ahead and have the valve job. Any bent valve will show up immediately. Also, depending on how you removed the head (unbolting sequence), a good time to get it checked that it isn't warped. If it is, a light mill to clean it up. Put it back together with ARP head studs. Reusing the head bolts is a no-no, as they were originally stretched during the factory build. Next, buy new cam and oil chain sets, with new tensioners and guides. And buy a timing chain guide to add protection from the timing chain ever slipping off the crank sprocket in the future. It's difficult to do all this in the car, but it can be done. Hopefully, you have a good Honda (factory) service manual to guide you. Buy the head gasket from Honda. You can buy the chains, etc., from RockAuto and be okay if you stick to the high end ones (price). The manual will show how to time the engine and the cams correctly. Follow it carefully. Torque sequence of head (studs) and lifter assemblies is critical. Best of luck. Come back to the forum and ask any questions you might have. BTW, my engine is a 2011 K20Z3, and I have completely rebuilt it once.