I'm working on my 87 Bronco b2 with 97 Ranger 4.0l efi 4x4 auto. I think I may need something off of the dash wire harness .My question is are they year, and model specific or the same with unused plugs

 

Totally different wiring, and clusters between 1987 and 1997
The cluster(dash) wiring in 1987 or 1997 just had temp and oil from engine, so same, one wire each
1987 may have an AMP Gauge instead of a Volt Gauge, but you can change wiring on 1997 alternator to use AMP guge

Can you be more specific