?? for 1971 & 72 Suburban owners

[GMCPaul]

We are finding some differences with a customers 71 Suburban taillight wiring from that of those we have here and we are hoping to get clarification on this.
The question is does anyone with a 1971 or 1972 have a taillight harness that runs from under the hood on the firewall like the pickup then down the frame to the rear or does your entire taillight harness run inside the Suburban along the underside of the roof panel??
If anyone does have the exterior wiring could you take a photo of the routing and what harness plugs into the rear of that harness? and where do the wires go from that harness?
Everything here we have appears to have ALL the taillight wiring Inside the Suburban.
Any and all feedback would be Greatly Appreciated!!!
Paul Jr. @ GMCPauls