my mods are in my signature. and i have yet to get it tuned with the bigger injectors(dont have $$ right now) but i got on it hard a pretty good bit today jst to be doing it, and a few minutes ago i made a high speed pull and now it seems like its idling high and wont come down. i had it at about 5-5500 in fifth for about 30 seconds tops but it does catch (sometimes the rev limiter) high RPM's on take off's. did i hurt my engine? and i know i need a tune to be top notch but am i doing damage by running ti with-out a tune? im new to the whole 4.6 thing, been a 5.0 guy forever and i was am trying to figure out the limits of the modular motor, not that im gonna be pressing them all the time but it will get driven. and if it helps the short block has 84,000 miles and the p.i. swap components had 20,000 on the car they got pulled from.