I have a set of 12.5:1 89mm wiseco pistons for sale. The original part# is k573m89 which are the 13.7:1 pistons. I purchased these from jeff at import builders and he prepped them down to 12.5:1 for me. If you would like to contact him for verification, by all means, go ahead. I believe these retail for around $550 give or take and Jeff charges $150 for the prep work. I'm asking $600 shipped for these. If you want to use paypal please add the 3%.