[Rev]

I wouldn't tighten more than the original 1/2 turn past the removal of the slack. That should put the hydraulic lfter piston in the working range. The lifter will "self adjust" to point where you can rotate the push rod with your fingers after adjustment with the valve closed, but there shouldn't be any play in the system after the adjustment. When the engine is running and you have oil pressure, there really shouldn't be any "lash" or any noise. The idea is that the valve train operates with 0 clearance and wear adjustment is automatic due to the oil pressure on the lifter piston. What's the oil pressure like? I can't think of any other reason for the valve noise if the lifters are functioning correctly, adjusted correctly, and the oil pressure is adequate.

Rev