Don't think you can
Not exactly sure, but I don't think they intermix at all. If it helps, I know there's an XJ down at my U-pull yard with an electric speedo/TC setup that I could pull the gauge cluster from and get it to you. I "think" they charge @ $25 or so, and I'd assume you'd need the wiring from the TC to go with it. Wonder if that signal goes thru the ECU????
Lemme know,
Jeff
edit-- It may be a few days until I can get to the yard, what with the hurricane heading straight for us.....