I am really debating on what I am gonna do. I already have most of the components for the 4.15 stroke. I had to send the pistons back and now if I dont pay the more money I cant get the pistons needed. Not to mention when they get here I have to pay for balancing. If I get the refund then I can buy the 440 source 512 kit(what I should done fro the start.I really dont know what to do.