yes, get a filler gauge and get the right specs for intake/exhaust valve clearances and do work. If your lifters are already very worn that they are flat instead of oval than the valve adjustment wont reduce the noise by much. Check compression, see if it's even through all the cylinders. If it is than the valves are closing well. If it's not than there is a possibility that some valve is not closing all the way, which could be fixed by a valve adjustment.
1990 M5 Euro
You wash your car like it was your firstborn child, you tend to its needs like it was your own body, you protect it like it's your family, then you drive it like you stole it