I am looking to pull the trigger soon and need to know if anyone knows the major difference between the Whipple WK-200750P (10-12PSI) $6400.00 vs. WK-200725P (I think this is the 8PSI unit) $5400.00? The price difference is 1k and I am wondering about the HP difference, and if the 200750 is bigger than the 2.3L 200725? I want to make the "safe" HP of around 430-450.