I think to make an accurate KI3T replica you need the GT speedometer. I clould be wrong but I think when they converted the GT's to GT500KR's they didn't think to swap out the speedometers.
Correct. KITT (TV show version) used a GT 6-gauge cluster with mycolor set to blue. Also, the only changes in the interior to reflect it was a KR were the seats, and the dash trim. In the GT500, the dash is leather trimmed, but that wasn't added.