04 HEMI ECM swap

[345hemidude]

Hey there, younger fella here, I happen to have myself an 04 Ram 2500 with a hemi in it. I am beginning to consider an ecm swap in favor of 4.56 gears over the weirdly ordered 3.73s currently in it. I have searched around on this platform a bit and have caught some wind of swapping the ecms in the 03 and 04 trucks to the 05 ecm which opens up tcm access and tuning, but I am at a loss on actually how to do it, questions with repinning the tcm and adding o2 sensors to the sensor on the throttle pedal compared to the cabled system that runs under the dash. I am just exploring the option and not committing on anything yet, especially without a solid plan on how this will work. Currently just info searching.

 

[345hemidude]

I believe I have posted to the wrong place.

 

[HemiLonestar]

At least you got it in the right overall section and aren't the guy asking 2nd gen questions in 5th gen (or vice versa) lol.
You don't need the PCM swap to change your gear ratio. You do not have a separate TCM unless you have a VERY early 04 build. Should be a one piece combined PCM that handles engine & trans function. 3.73's were the standard 2500 gear set for both gas & diesel. If memory serves 4.56's were reserved for the Power Wagon.
If you actually have a cable pedal then you still have the 03-early 04 APPS before they switched out to an e-pedal.

adding o2 sensors to the sensor on the throttle pedal compared to the cabled system that runs under the dash.

You're gonna have to clarify this one....O2 sensors do not wire to the pedal.....and if you actually have a cable pedal then you don't have a sensor on the pedal.

Now for any custom tune or tune for a reasonable 3/4 ton cam the 04 PCM can accommodate.