Any benefit to a ride plate w/o setting back the pump? I have a 18' Tahiti W/ a SplitBolwl and diverter. I have not tried the various straight or droop combinations first. It will have a new BBC W/ an"A" impeller. It previously had only a "C" bowl with limited runs W/ diverter so I do not have a "baseline" for comparison. How is the setback determined? Any opinions?