painless wiring installation

[Steelscapes]

Ok.. hopefully I someone out there has done this before. Me and my son are redoing a 76 k10.  Just ordered the painless wiring kit. Having an issue determining the year of my instrument cluster. The guy we bought the truck from had told us he swapped it out with a Custer that has the gauges. However not sure what year its from.. the painless wiring is year specific in regards to the way the cluster is wired.. can anyone tell me how I'd know what year the cluster is..

[Irish_Alley]

take some pictures but most times if the cluster pigtail is still original (no splices) then its the correct gauge cluster for that year truck

[enaberif]

Does it have a volt or ammeter?

[Captkaos]

Without seeing what you have we would just be guessing.

But this is how to identify them.
73-75 = AMP gauge, mechanical oil (has a metal capillary tube that is proprietary to GM), 100mph speedo
76-77 = VOLT gauge, Mechanical oil (same as above), 100mph speedo
78-79 = VOLT gauge, all other gauges are electrical, 100mph speedo
80 = VOLT gauge, all other gauges are electrical, 85mph speedo, no DRAC
81-84 = VOLT gauge, all other gauges are electrical, 85mph speedo, trucks with cruise will have the green box on the speedo (DRAC)
85-90(91) = VOLT gauge, all other gauges are electrical, 85mph speedo, DRAC for Feedback carb.  (some early 85's didn't have this...)
90-91 = VOLT gauge, all other gauges are electrical, 85mph speedo, Digital VSS (no cable speedo) this is what everyone want for their LS Swaps.

I really need to put together a tech page on this...