Engine bay wiring question

[ASWZ71]

I picked up a 72 GMC with a Chevy front conversion (I know ...). I got a box of parts since it was in pieces. I am getting close to putting her back together but I’m trying to figure out what these engine bay wires are so I can order replacements. All the engine side ends are gone so I don’t have much to go off of. I am really bad with wiring so I was hoping someone could tell me what I have and what I need. Truck is a 350 with ac. Thanks for any help
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[truckster]

That's the TCS wiring. You don't need it, unless you're doing a 100% stock restoration.

[ASWZ71]

Originally Posted by truckster

That's the TCS wiring. You don't need it, unless you're doing a 100% stock restoration.

What are the downsides of not using this. I’m not going for a perfect restoration...lol with this trucks jumble of parts it’s not even possible.
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[truckster]

There's really no downside. It was an early attempt at emission controls. It retarded the ignition timing under certain circumstances. I've actually never seen one with the TCS connected.

[71CHEVYSHORTBED402]

So that's what TCS wiring looks like in the cabs huh? My 71 had the wires, relay and delay mounted on the firewall, wires running to the carb and transmission. But nothing inside the cab.

Even with a 100% restore, put it into a box to say your have it I hear they're worthless, even if they happen to "work". A lot of wiring for nothing.

[truckster]

Originally Posted by 71CHEVYSHORTBED402

So that's what TCS wiring looks like in the cabs huh? My 71 had the wires, relay and delay mounted on the firewall, wires running to the carb and transmission. But nothing inside the cab.

Even with a 100% restore, put it into a box to say your have it I hear they're worthless, even if they happen to "work". A lot of wiring for nothing.

Yeah, I believe 71 and 72 were the same basic system, but installed differently.

[71CHEVYSHORTBED402]

Originally Posted by truckster

Yeah, I believe 71 and 72 were the same basic system, but installed differently.

Interesting. Well, I can only say my 72 doesn't have that wiring inside, and they did a poor job sealing up the firewall in the engine compartment. No other evidence of TCS, though I'm no expert. The transmission "pass through" only has one terminal, which is the kick-down. I believe all 400 71-72 transmissions had two terminals. One for the kick-down and one for TCS. My 71 did. I don't recall if all 71-72 trucks had it. It may have been California etc. requirement.

For what it's worth, here's my old set-up. Not able to ID one wire, it was clipped.

[mike1971c10]

My '71 has them on the firewall also. I have a red wire plugged into the IGN UNFUSED but have a wire piggybacked off on it, but the main wire in looks smaller than his picture. Do I have the right wire plugged in or do I just need to pull the tape off and follow the wires?

[71CHEVYSHORTBED402]

Originally Posted by mike1971c10

My '71 has them on the firewall also. I have a red wire plugged into the IGN UNFUSED but have a wire piggybacked off on it, but the main wire in looks smaller than his picture. Do I have the right wire plugged in or do I just need to pull the tape off and follow the wires?

Think I was confused. Is there a relay of some type mounted inside the cab plus the relay and delay on the firewall cab side?

I found two pink wires at IGN UNFUSED.