Just to follow up; I emailed CJ Pony Parts, I was told that the only differences are the wiring harnesses and in theory it should work. Though I have also head the same thing as El-Guapin said, that there are separate part numbers, and that will only work with the corresponding years.
So I've read that only the new 2018+ GT350 steering wheels can only fit on the 2018+ GT models. However, on some websites I have read that some GT350 steering wheels fit the 2015-2019 GT models. Does anyone know if this is true, or are the steering wheels two separate skews for the 2015-2017 and...