Back when Carter sold a sintered ceramic fuel filter, some of their ad copy claimed that the factory-installed wire mesh strainer that most carburetors used upstream of the needle valve was for catching "rocks, marbles, and bowling balls". For real fuel filtering, a much finer media was required. The same claim can be made about "full flow" oil filters. The filter media simply can't be made fine enough to catch anything but huge chunks of contaminants that can damage connecting rod and main bearings, and still allow enough oil flow to keep the engine lubricated. To really do a good job of oil filtering, two filters are needed- - - -a full flow to catch the big chunks, and a MUCH finer mesh bypass filter to strain out the fine stuff. I think a spin-on filter with about a 1 micron mesh and a 1/16" flow control orfice to avoid oil pressure loss should be added to engines with a full flow boulder catcher!
Jerry
