The difference might be the something to do with programming . Id make sure they both plug in the same because I think 2003 was a different animal electronics wise . Also make sure the NSBU is the same .
Same trans except cooler fittings might be different. There was a fitting change mid year. There are adapters to fit either way. Programming difference is total bullshit. Guess people want to post hearsay to sound smart.
If you can't prove your answer, stay the hell out guys.