I don't know. I ordered the FE 390 rebuild kit from Summit Racing....pt #FEM-MKP601M-300. that includes .030 over pistons for a ford 390. I don't have them yet but they are to be delivered today. I had planned to take them to the machine shop today so they can check and do the boring. Maybe I should call summit and see about shipping just the pistons back and replacing them...I'm anxious to get this thing back together. If I get the 360 pistons what does that change the compression ratio to?