I want to use a megasquirt to control the fuel and ignition on my '98 Ram 1500. I would like to know if I can do this, while keeping the stock tach/guages/etc.. functioning. I know I will lose cruise control, and I expect to have a check engine light. Does the stock pcm need more than the crank sensor to give a tach reading? Temp & oil pressure senders will be hooked up. Stock alternator leads will be hooked up. A/C compressor will be hooked up as stock. Fuel injector leads will simply be unplugged, as will the ignition leads to the coil, map sensor, IAC motor, etc.. I believe I can still use the crank sensor. I plan to use the megasquirt to control fuel and ignition for a hemi swap. I have NO interest in using a stock pcm, or retrofitting a dash/harness/etc.. from a later truck. It is my understanding that I can disconnect the fuel injector leads, and substitute an alternate fuel control, while everything else stays the same. Not sure about the ignition.

Thank you for any input. I have seen several hemi swap threads, but all included a factory pcm, that I have no intention of using. My question is more about the '98 pcm, than the hemi.