I've got a 2000 400ex that the person pefore me put a Namura 440 kit in. Well the timing chain broke a link the other day so we tore the motor down to replace it, while its apart im going to replace a few other things. But I was needing to figure out what the compression ratio is on it. I know the Namura kits came in 12.5 to 1 and 11 to 1. Is there any part numbers stamped on the piston that would ID which one I have? Or can I tell simply by looking at it? Thanks for any info.