There's no difference in the TRUCK ends of 2G & 3G harnesses; only the ALT ends, and it's easy to convert the 2G end to 3G by crimping a ring onto the 2 heavy wires in the big connector.
But it's even easier to connect the '93-96 3G harness to a '92 truck's harness & starter relay.
More importantly: the alt isn't necessary for the battery to work & crank the engine, but you might have a draw that's killing it. After fully charging it for SEVERAL hours, DISCONNECT the battery overnight. If it still won't crank in the morning, it's junk.
The store that your DuraCrap Gold came from is the zone, right? I wouldn't trust them to test a flashlight battery; much less a vehicle's. If it came from WalMart, they're not a whole lot better. Charge it FULLY with a 110V charger overnight, and then take it someone with a MidTronics high-frequency tester.
When it fails, take it back to "the store" for refund, and go buy a decent battery: MotorCraft, Interstate MTP, or Sears DieHard Gold.
You don't need the misfire sensor on the front of the engine, or the special harmonic balancer with the 4-tooth tone ring. Someone who DOES need them will probably pay you more than a common balancer costs, so help a Bronco brother out and consider putting that balancer up for sale. You don't have to remove it until you get the money and buy the replacement, as long as you explain the delay to the buyer beforehand.