1. Engine cold.
2. Retorque the heads.
3. Timing mark set to OT (TDC) in the window, though maybe check that it is, as the flywheel can be put on in any of five positions and only one is correct (It's been done!!!).
4, I use 0.1mm IN and 0.2mm EX though the later unleaded's (after '85) can run 0.15 EX if you like.
5. Spin the pushrods to see if they're straight, make sure rocker sideplay and bearings are ok.
6. While checking the clearance, push on the pushrod end with enough pressure to just stop the pushrod spinning. I learnt this trick from an old VW mech when I had VW's. It takes up any slop from the pushrod dropping from gravity and the tappet not hard up against the cam. Try it, you'll find you can tighten them a few thou more.
7. Accept that the Airhead is a valve noisy engine....though a noisy valve is a happy valve (obviously within reason!!)
Bill.....................;-)