Piston set is standard size with a 9.5:1 compression. For a 3.498" bore. Pistons are forged from a high silicone alloy. 2009-UP XL 883 cylinders cannot be overboard to 1200cc. Note: Run engine at moderate speeds for at least 500 miles, avoiding excessive running in lower gears, in order to properly break-in new pistons and rings.
Wiseco 883 to 1200 big bore conversion piston kit 9:5:1
Wiseco forged pistons are second to none and this is the second set of Wiseco pistons I have purchased in my life. The price may be considered high but you get what you pay for and you would be insane to use cast pistons when these are so much better.