[FLBill]

Hey

The '92 to '94 I/P's are interchangeable.They are PLUG and PLAY. They are all wired the same.....for a TACH. It is just that some trucks come with the basic dash cluster instead of one with the tach.

The '90 I/P's can be worked on cluster plug wise to function with a tach dash.

The '91 also can be worked to operate with a tach. The '91 was a transition year (to the DRAC {Digital Ratio Adapter Controller} module). The DRAC module is used for calculating engine information (a tach signal) along with rotation information (via the trans and rear gear and or tire size.)

'91 did not have a DRAC proper and the settings procedure for this is unique to '91. DRAC would start the next year. The I/P's of '91 would have the rear gear to speedo calculation adjustment occur at the back of the I/P.

'92 to 93 there is a DRAC (Digital Ratio Adapter Controller) which is behind the glove box. If you change your rear gears or tire size, you can make calibration corrections for the speedometer here. It is pretty straight forward and very doable.

'95 to '96 would have a VSS (Vehicle Speed Sensor). You can use a DRAC up to '96 but you can not use a VSS down to the lower years

I/P's of '92 to '94 are plug and play and inter swappable.

'95 the IP changed as did the interior design.

.
Bill