The Owners Handbook gives the setting information you need & possibly the articles on the Club members section would be helpful, you can take the chain tension off with a 12" aluminium length of 1" by 1/4" bar withe each end having an angle cut at say 45 degrees this can be used to hold the Weller spring straight by locating it in the rolled ends of the spring!
0.020" is the recommended valve clearance for AC Camshafts.
Timing can be set per the handbook or a simple way is to have number one piston at top dead centre & set the cam on the rock! It might be easier to have a vernier chain sprocket!
Robin