See BOLD below I think the tuners have done a lot with what they have available to them, none of this is in no way meant to be a bad reflection on what they do or the software they use. Since they can't reprogram the ECU, they are left with manipulating table data. Obviously some are better than others. It is not an issue with the software either, it is no ones fault that the ECU programming code remains locked up in a vault in Auburn Hills! The whole intent of the thread is to elicit discussion of the limitations so people know what they are, know what to look out for, and to know what to do to monitor and protect their investment. Is 5-6 psi safe on these engines, yeah, I say it is, as long as the fuel, timing, and combustion chamber temps are in check. I put 32,000 on a stock 5.7 running up to 9 psi, and believe me, the foot was in it all the time. It was not babied around!