You can contact a vendor if you want to but you have much more experience here. Chances are the person you talk to will ad lib. Chances are they have not used a wiring harness. Their kit is outsourced. George has told you the basics. Wiring IS NOT hard for an older truck especially with no extras. It IS NOT one of the hardest stages for an old truck. You have spent the money for a harness. Use it. Don't be intimidated by wiring. No need to keep searching for a harness.
Having extra wires/circuits does not matter. Building you own is not the way to go. Nothing you can buy will make it easier than what you have. You need to define "most original". Folks here think that means "most original wire type", cloth insulation, custom designed, original "no fuse" configuration and original terminals. If that's what you mean, that's big money just to feel good or for a concours car show.
Otherwise ALL the harnesses are sort of generic with various numbers of circuits and extra switches and such. Most harnesses have a prewired fuse panel with wires coming out. I don't know your experience with wiring but sounds like not much. The harness will end up being about three branch harnesses. Two go thru the firewall, one branch goes to front light and engine, the other goes to the rear lighting. The third stays in cab, under the dash for dash components. Not very many wires in all. Mount the fuse panel and route the wires. There may be some other loose wires for inter-dash/ignition related connections. Study the wiring diagram for your truck and the instructions. It's just a from-to exercise. If you get stuck, keep posting.
Please post the part number of the harness you bought so we can look at it. You said Classis Parts and Greg posted a link to Classic parts. Not sure if that is the same company you are speaking of.
I looked at Classic Parts Part number 52-081 and it has flexibility. The extras you are worried about are on a separate connector. The kit is heavily connectorized (Flexible). So just leave the fuse panel end of those connectors tied up under dash. Roll up the wire into a small loop and tie wrap. If you don't like that, disconnect the wires at the fuse panel. Terminals are releaseable with a tiny screw driver.
The words "Classic Update" does not mean much. It's not original, per se, but has "updated" modern wire and connections. It will wire up a "Classic" truck. So will any harness. The 52-081 is a good quality harness. You will not use or wire up, some of it. It will become apparent as you go along. Get your fuse panel sorted on the bench as George says.. The branch harness are already tie wrapped and identified in that 52-081 kit. The artistic part is how nice you route, clamp, tie and loom the wires.
if your kit is not 52-081, most of the above will still apply. Crimping, with the proper tool, and shrink sleeving over the connection is plenty adequate for automotive. Soldering is overkill and you will screw up and melt insulation and get crooked, stiff connections. Unnecessary.
American AutoWire is the premier Kit. The most complete, top of the line, high quality, flexible, beautiful Classic Update kit available, with excellent instructions.
52-081 is the American AutoWire Classic Update Kit for 47-55.
