I run .0015 rod clearance on both the 2.100 journals on my current engine and on the 2.3 journals on the former engine. Rpm range is limited only by what crank and rods used, my former engine utilized stock crank and rods and I limited the rpm's to 7K and my current engine utilizes an aftermarket 4340 crank and H beam rods which I've turned 8500 rpm's. The rotor is a standard gear style and it is 1-1/4 in length, the pickup size is equivalent to a -12 and the pump turns at 52% of crankshaft speed. This feeds through the 7.3 Diesel oil filter via -12 lines into the oil filter pad at the front of the block only. I used to split it at the inlet and feed into the oil pressure boss at the rear of the block when I ran the old high pressure pumps, but no more. The lower pressure does away with the pressure loss at the center and eliminates any cavitation at restricted areas such as the rear main crossover. I hope this answers your questions, I'll be happy to share anything else you'd like to know.