put in b16 pistons

if i have a stock ls can i just put the b16 pistons on rods without balincing every thing

yes you can put the b16a pistons onto your stock b18a rods w/o balancing them. The parts come well balanced from the factory, and since you won’t be modifying either the rods or pistons when you put them in you won’t be changing their weights and thus rebalancing isn’t necessary.