oversized pistons from the same manufacturer of OEM replacement pistons weigh the same as the STD pistons they replace. Aftermarket performance pistons rarely weight what the stockers weighed. MP pistons, stock or HP/stroker whatever are not as close as Probe or other high end pistons. My stroker set were only within 7g of each other, some good manufacturer sets are within 1g or less. I had to lighten them all to the lightest one, 7g is alot to be taken off a short stroker piston. ended up taking a few g's off the pressed pin.