I dont know about top weight, but I'd say to go with a 3-4 inch pin so that you can put the pin over your fingers and still have some length left to keep the CG around the center/mid line.
As for drill and cover prep...Put the pin over the bridge and MB no more than 2 inches away from your thumb (right side if righty, opposite if lefty). Then bring the cover down to 2000 or 1000 if needed.
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Bowling Since March 2006 - "Get coaching, don't worry about it"...blah blah balh...Just answer the questions please
Arsenal:
Hammer Pain (1000 grit)
Hammer Black Widow
Track Equation
Storm Spare Ball