Ok I had to bring this post back from the dead, but for good reason. There has been some good information come about in the last 12 years. The 2.5s do like to rev and it has nothing to do with the rod ratio. This is my 2.5 stock bottom end, ported head, intake, header, and custom spec'd cam.. This thing loves the High rpms.. This is 6 psi / 11 psi / 15 psi