Well, you can't use Gsr/type R rods with the Ls crank, they are too long .9 mm to be exact. but most aftermarket pistons are within +/- 1 gram, which is neglegable. so are the pistons, So if the cranks balanced, and then in a normal street application, it really won't matter.Go get some eagles and some good pistons and you won't have any problems with the bottom end. Plus why not with a brand new endyne head. Seems kinda weird to want to keep a stock bottom end with it.