Megasquirt is a stand alone ECU. It uses the factory Hemi sensors with the exception that you must use a cable operated throttle body. Most (not all) cable operated throttle bodies utilize a GM Idle Air Control Stepper valve.
You can but you don't have to also use GM Air Temperature sensors, and Water Temp sensors if you wish but you can calibrate the Megasquirt to work with the Hemi sensors.
There is NO REASON to swap out the either the Crankshaft position sensor, or Camshaft position sensor as MS has settings for both of those.
