Wiring help gmc vs chevy

[Missyblue]

Hey I need help. I have a 57 gmc and the precious owner bought a chevy wiring kit. The colors seem different so hoping someone can answer a couple questions
1. Will a Chevy harness work with my gmc gauges/lights/etc?
2. I was going to order a wiring chart should I then now order a Chevy chart for color coding?
3. Am I crazy and shoukd scrap it and do something else. They are just so expensive and this is a good set just Chevy
4. Any other thoughts to consider I'm forgetting

Thanks

[mr48chev]

There shouldn't be any difference in color coding on any GM vehicle. That has been one of the great things about working on GM vehicles as apposed to some other brands. If you are working on a circuit on a GM rig the wire color code is the same as every other GM rig.

[dsraven]

I haven't compared the two but do know the cluster looks different. the wires should still connect and work though. the guages may need the correct sending units though,if swapping a fuel tank or engine. ensure you get a harness made for generator or alternator specific to match your truck. otherwise you will need to do some wiring to make that work anyway. if using HEI or another ignition set up that is not stock you may need to swap some larger guage wire in some circuits as well. if removing the "step on" starter pedal then some more wiring and a different ign switch may be required because the original switch didn't have a "start" position. if upgrading the steering column for a newer tilt style or something with an automatic shifter integral then the plug for the signals will likely need some attention as well as the ign switch wiring (if the swith is in the column)
the lights should wire the same with the same colours as well, maybe the connectors on the ends of the pigtails will be slightly different but that is something you can easily overcome. gmc front signal/marker lights may need some extra length of wire to reach the lights that are in the "mustache" part of the front grille surround,not a big deal though. your truck isn't stock, engine/trans wise, correct? you may need to swap around some plug connection ends and wire lengths for certain sending units etc anyway. the lights should be pretty close though. the heater fan control should work, you will need to know if the new harness has provisions for a wiper motor switch if going electric, some were simply vaccum motors
I guess it all depends on what you are planning to use from the stock version of the truck compared to what the new harness has provisions for.