After driving a bit check your dipstick, make sure no air pressure is released. Get a real PCV valve.. they are like $3 from rockauto.
Spliced wiring? Check voltage on ignition coil, mine was running at 7v due to some high gauge wire going to the tach. Ran a bit better after fixing it.
How does it run overall? Does it idle smooth? I've seen L20b local the other day that ran perfect.. no wobble on idle, valves are silent, ect... thats how these should run!
ADjusting valves hot is a pain.. I adjusted one exhaust valve, moved onto the other one and finished it, checked the first one and the clearance had already changed from cooling! I'm going to do two at a time and get em just right next time I can work on it.