Looking at stuff for my 355 build up. For the pistons Im interested in, I have a choice in .090, .120, and .150. Weights are 76, 99, 117. Obviously lighter is better, but at what point would the .090s be too thin. BTW, the first two are 9310 steel, the last is 1018.

Another question Ill throw out, the pistons themselves are 395g. Still havent decided between rods. H-beams are 685g, but are stronger, and the I-beams are only 555g. What would be the rev limitations between the 2?

 

The safe rev limit depends more on the balance than the total mass of the assembly. The 1018 wrist pins are about as mild as you can get, and likely will deflect under heavy loads. You almost certainly wouldn't want them in a floating pin application.