Hey guys first off I've read myself stupid so please don't say "search". I've exhausted every way I can think of to get the CORRECT information I'm looking for. So I'm rebuilding my Super Eta and I thought I knew this engine but after many wrong assumptions here I am. So the bottom end is where I'm having trouble. I know I have a 81mm stroke crank, 130mm rods and a 84mm bore. But I just picked up a set of "I" pistons attached to its original 135mm rod. My original plan was to use my Seta crank, 135mm rods, with 85mm custom Pistons for the rebuild and go with 10:1 compression pistons. Now I'm reading that the "I" Pistons are different from the seta Pistons and have a -1.721cc and my Seta Piston -8.275cc so with the compression Calculator I found I can use the 135mm rod with the I piston at -1.721cc and have a compression ratio of 10:1 with my 42cc 885 head... Could some with real knowledge chime in and and point me in the correct direction before I drop $2500 on Pistons and machine work...Thank you!