Have you considered a 78mm crank? And sell the 82mm?
That 78mm crank would give you 0.078" clearance with zero removed from the rods.
That cam really likes to REV, so the shorter stroke may help.
Your 2786 would become a 2650, still a BIG motor. I know you'd have to rebalance the crank/pulley/flywheel and probably re-do the deck height, chamber size and CR.