Just Purchased Virgin 340 Short - What to do with Pistons

1968-71 340 pistons = comp distance - 1.840" - 2 valve notches - 725 grams plus pin = heavy , above deck around .020". 1972-3 340 = comp d - 1.740" - 4 notches - 725 grams plus pin = below deck .080". if rebalancing is in the budget, you want to keep it and rev high for years, go lighter pistons and pins. a longer stroke = shorter/lighter pistons, and more friction. a J E piston for 4.060" X 3.480" weighs 513 grams and revs quick. 906 big block heads?