Is there a differenc between the IAC on the 7.4l and the IAC on the 5.7l engines? My cam is just a little too big when the 1.6:1 rockers are added in. I have no adjustment left on the IAC and need more to smooth out the idle.

 

If you IAC counts are maxed out, you will need to find another way to introduce air into your engine ... possibly via a drilled hole in the throttle body or resetting the idle set screw for the idle. You want the IAC Counts (steps) to be low so it have room to adjust for a fluctuating idle. the deviation from the target idle can be controlled via spark adders (which add or remove timing based on over/under speeds). Good luck!