The guys I've talked with and bounced ideas off of, measure the bolt,nut,and any weight added. Not the arm itself. we also would discuss individual arm weight if it was staggered, along with total weight.
Just install a Mattoon or DD lockup. You could probably get by on 6 stock oem springs, but you might consider 3 & 3 to start. Of course that depends on swinger length, weight, tire,etc.
From what I've read about beefy,he's dragging in the dunes. Imo, clutch tuning on such an ever changing, inconsistent surface has proved futile. Lock it up and go. Focus on tire,suspension, and chassis setup instead.