lifter preload w/adjustable rockers

My thinking;
I currently have a little smaller cam, a Hughes HE3038AL,which is an HFT, and with 1.6 Mopar arms, .549/.571 lift 230/237/[email protected].; and with their HD circlipped lifters.
I run the lifters on the edge of ticking, so they are pretty much fully pumped up. That way, even if the valves float a bit, as long as there is enough built-in valve to piston clearance,the engine won't go down.
I think the idea is working, cuz I've been revving this thing to 7200 since 1999.
Your results may vary.
I once missed third gear and saw the tach needle swinging across 8000....... on it's way back down.... After that I bought a rev-limiter..... and fixed the dang shifter. The engine idled just fine..... and no, I never tested it again,lol.
I see;

a pretty heavy 12* split there; can I ask what the thinking is on that?
I went with what Oregon Cams recommended. They recommended 2 cams and I chose the smaller of the 2 because we thought it would better fit my needs. Why such a split...I don't know.