Not right, the differential sensor didn't start until 1998, then it ran odo and speedo as the VSS in the '91 does. It's been too long but since he's replaced both those things I'm guessing it may have a PCM problem?

Robert

'68 Fury Convertible
'69 300 Convertible
'15 Durango 5.7 Hemi
'16 300 S Hemi