Higher compression = faster spool time. Why would forged pistons come with stock compression ratio AND higher compression like 9.5.1? Usually when you build a stroker, you have to bore 40 over to get the right displacement and when you're planning on running a massive turbo its better to have higher compression that way you make more power quicker in your powerband. Im getting ready to run a 70trim on a stock 6 bolt and its not going to be at full spool til 5500 rpms. If I would have waited when I rebuilt my motor and put 8.5.1 7 bolt pistons on my 1g rods I would see full spool at 4700-5000.