Are all PCIIIUSB units the same? The part numbers are different for various models when purchased originally but is that because of the trays, etc. for installation? I have purchased an '06 FLHRCI and want to install the PCIIIUSB from the '05 FXSTI I traded. I think they are identical (only a map change required) but would like confirmation one way or the other as Dynojet didn't answer this question in my email to them.