If the sumping problem is caused by insufficient scavenging from the crankcase, not by excessive oil going into the case, these might help.
However, if the problem is too much oil going into the case, for instance from leaks around the piston cooling jets, these parts will make the problem worse. In Feuling's product details, it says "This camplate also matches the oil port holes throughout the camplate to the port holes in the engine case increasing engine oil flow to the lifters, piston cooling jets, crankshaft, rod bearings, oil cooler and oil tank.
Some of the previous thread responses have indicated piston cooling jets might be the problem, so a pump that has better scavenging, but not increased pressure and flow, would be a better choice. Could be what HD's "upgraded" pump is all about.