If making the change I would also only consider using a 05 model. The cable drive throttle I understand is not a big issue as the 05 APPS is built into the pedal assembly and the 03 has the separate APPS that is driven by the throttle cable. Using the later pedal assembly solves the problem. I don't know if anything has changed but the available tuning for the 03 (hemi) is pretty much limited to CMR tuning. The 03 4.7 can be tuned using SCT, and I believe that is because they have drive by cable verses the Hemi's drive by wire. Whatever you do talk with a tuner before deciding what you want to do. I'm back looking for tuning solutions as I have a pretty big cam I want to install. So the hunt continues.
2003 RCSB, 2wd, Street Truck
6.4L/cog driven Sci-V7/46rh trans/Armed-HTH
Support vehicle- 2007 QC G56 4x4 diesel