The King hp are great, and they are 1/2 groove. For 30 years I ran full groove, even made my own jig for full grooving oversize bearings. Always seemed to be getting a rod bearing within 50-75 runs. Last build 5 years ago my machinist guy who builds T/D and T/S monster motors suggested getting away from full groove. I thought what I'm doing isn't holding up, lets try it. Now this was a 4.75 stroke cut .030/.020 with 2.200 rod journals. The motor lived without incident until it dropped a valve after 200 plus runs. The bearings were still excellent. No more full grooves for me. Sometimes you have to get out of the box. I run 10-40 royal purple with the Milodon swinger, and sometimes the pressure would go to zero under hard braking. The bearings showed NO signs of distress. I put a stop in the pan to keep the PU from going all the way forward. I spoke to the guy that designed them years ago, and he sez they suck. I think he's right, but I'm still running it.
RIP
I also had issues with oil pressure, once running through the traps with only 45 psi at 7500 rpm in a 4.15 stroke full size bearing bottom end. I run King, FM, bearings 1\2 Grove and have run 3\4 Grove. I was surprised to see so little damage, and had two minor issues on a couple of rod bearings, the mains looked great. If enough oil is going through the journal for cooling, I believe the extra surface area of a 1\2 or3\4 Grove is a help in providing life in case of momentary oil pressure loss.
Before I came up with a good oil pan and accusump, I really had to watch how hard I hit the brakes, and more than a few times I am certain I ran a lot of air through the oiling system! Never any full fledged bearing failures, just a very slight amount of damage, not enough to make them fail.
