Pistons specs question for 340 build

Gudgeon pins are anything but, unsprung weight! They are a huge part of the reciprocating weight. You need to know the pin (gudgeon) weight of the new pistons to compare to stock.
(As an example, in my old TRW book, 440 pistons, and their pins, are the heaviest in the book. 225 gram pins! I have some old dome maxwedge pistons that are 1100+ grams with pins.)

And yes i remember you are dealing with a small block. Physics still applies.