The Caprice door harness will have plugs that end in the lower A pillar section so you could custom wire onto those as needed. The entire Caprice loom would work best, but only if you considered using the entire Caprice dash which may not be desirable if you love the GTS dash you already have. Most of the electrical trickery in the loom is intended for the Caprice dash so you might need to do a custom job to mesh in some of the really sexy extra bits.
The Caprice doors will fit but gaps may need massaging if your really anal. You may also need to fill in the rubber strip holes on the doors and grind off the little studs for the chrome trim if your not going to use it.
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