Ok, well I'm still looking around and came across this
http://www.ff-squad.com/tech/temp/pistons.htm
From my understanding it says the with CTR pistons and a GSR head I would run 11.8:1 or more which doesn't make too much sense because with the JDM ITR pistons would be around 11.3-4:1. I might just go with the p73 JDM...