Rocker shims = NO rocker shaft oiling

Bewy said

Anti pump up lifters [ APUL ]. Properly designed APUL do NOT use a paper clip circlip, which is what stock lifters have. They use a much stronger circlip to stop the lifter pumping apart due to pump up.
The minimum pre-load idea came from hot rodders & there is a very good chance that the engine could come to grief. Russian Roulette with a 6 bullet revolver & 7 bullets....
As I said earlier in this thread:
- using strong enough valve springs prevents pump up.
- you have about 0.150" of lifter plunger travel. There is no need to set the pre-load so tight for the reasons stated above.

Click to expand...

Agree with mosta stuff, I've read a few times 0.090 is the max adjustment travel.
Never checked it, cuz I'm one of the guys running at the top of travel, I don't think I've ever gone more than 1.5 turns on a stud, I usually stop the noise, add 1/2 to one turn, that's it.
When Isky brought out the anti-pumpup, it had a second hole thru the side for bleed off, later it was an internal mod to have the bleed inside . iirc
The thing about cranking down adjustment to near bottom, - that's how far the cam lobe can wear before noise, - at the top, wear off a coupla thou, and there's noise to go looking for trouble before serious damage, jmo.