Ok so my mods are in the sig and i have really been considering either a ZEK Wet Kit, or the Nitrous Express Wet Kit for my trickflow intake, with all the nitrous accesories and a larger fuel pump. I was just looking for a 100-125 shot and i was hoping to get it tuned for a flip chip so i can drive around with full timing and than at the track flip the switch and have a tune set up for nitrous with less timing. My question is my buddy told me on my 5.0 you cant have a tune that takes out less timing only the newer 4.6's can. The only way to lower the timing is to manually do it the old way of turning the distributor. Is this true??? Thank you for your help.