Cluster swap Basic vs tach cluster 77 Firebird Esprit
 

Hi, like to swap now my Basic Cluster vs tach cluster.
Who has already swaped it?
Plug and Play or have i to connect new wires?
Thx for any help?

I don't believe your factory harness is set up for it. Harness for guages is different than harness for warning lights.

been a few years, but have done a few.
not plug and play, you need the wire plug from the gauge pack, and a color scematic(sp) showing what the wires run to, as the wires are in different orders on gauge and non- gauge packs. be easier if you can find a 77-78 pack and manual. then I just cut and spliced the wires together. the colors should be almost all the same, think there was 1 that was different. I also had to extend a couple wires to reach all the way out to where the fuel and amp gauges.
this is very quick and dirty as I am not home to get pictures, but not that hard and will work well.

Hope someone can shed some light too, as I would like to install my 160mph speedo and 8000rpm tach with rally gauges into my '81 base firebird

Might be most economical to buy a used harness from a gauge car for the year that you have gauges from.
If you cant do that I'd suggest you get any harness so you have one you can hack up to build one good one out of. You can always fix up the ends as Warbird said, if any are missing but you'll have the plug. The plug that fits into the back of the gauges is different in sizes, even between the years. Sometimes when you buy the gauges guys will have cut the wires but left the plug in. This can be useful for the connectors/wires in the plug.

I did this in my 75 Formula car.
A wire harness, and the connectors, come in handy anyhow.. I bought a few cheap just to have the plastic fittings and the wiring to use here and there.

And yes, as Warbird said, get a diagram. Even the Haynes manual has a pretty good set of wiring diagrams that I used..Although I did need a magnifying glass...