gauge cluster compatibility

[RuralRoute C-30]

Since removing and inspecting the back circuits of my old gauge cluster and discovering it is rusty and beyond brittle, my question is on compatibility of the harness plug that goes in the back of it.

Are all 81-87 gauge clusters a 'plug&play' or are there differences in years on the harness plug's pin sequences?

Found a couple today, an 86 and an 87, one from a blazer and the other a suburban. Compatible?

Saw a couple on e-bay as well with clocks. Would the clock be functional if I just plug in my 85 harness no matter the year or is that a separate plug?

Just hate to pull the trigger and purchase something that doesn't work because I failed to simply ask if it would!

Thanks!
Mark
"Getting older doesn't always make me wiser, but my experience in years alone does tend to hold enough memories so I don't repeat the same mistakes."

[Stepsideride]

most are plug and play with guages that is.....idiot lights not so much as wires are different and in different places on the plug...just trace the lines on the printed circuit and arrange wires from there if you have any doubts on them.

[spinem]

Originally Posted by Stepsideride

most are plug and play with guages that is.....idiot lights not so much as wires are different and in different places on the plug...just trace the lines on the printed circuit and arrange wires from there if you have any doubts on them.

yup, just trace the line

[95 S_Trucker]

78-86 interchange, but if you have cruise control you will have to use your original speedo for it to work, which i would do anyway if it works to retain the same mileage.