I just rebuilt 2 cyl's on my IH656 loader. All of the seals, o-rings, etc didn't add up to much - maybe $20-30 total. BUT when the hydraulic shop saw the pistons, they recommended getting them polished b/c the pitting would've torn up the new seals. I forget what their estimate was, but both pistons ended up being about $150 total. My pitting was a bit deep though, which required them to grind them down and then building them back up to the proper diameter. Then they got polished.