i dont think any of them are cheap man lol. i love my EVO but it cost $350 i have a friend that bought a bullydog from amazon. hooked it up to his truck and programmed his truck and then returned it. lol
you can do alot of **** with it. timing, wot shifts, fuel intake, tire size, gearing, idle, rev limiter, speed shift poiints, speed limiter, etc. you can also do a 0-60 and a quater mile test, it saves them too. you can monitor alteast 20 different things on the truck. plus it doubles as an OBD2 code reader
it says in the manual they reccomend to not use the tuner with engine upgrades like superchargers air intakes turbos and otehr stuff. not sure how the headers would affect it. since these items change the amount of power given to the truck and the amount of air taken in the programmer would have to be tuned a certain way so that the truck doesnt run too rich or too lean. the programmer can fix tire changes and gear changes but oddly enough no performance upgrades. i would have thought they would have made these tuners with superchargers and turbos in mind.