1991 GMC S-15 V6 2WD 4.3L

Im installing spark plug wires. I have a good idea what the firing order is and need to know how to tell which spark plug wire goes to which spark plug so its the correct length. I bought the truck with the wrong wires apparently because when matching wires up to replace old ones none of my new wires matched the same length of the old wires. In fact the only wire that was the same length was the coil wire. One wire was visibly different from the rest. It was a red 8mm wire and the rest were all black 7mm gauge wires. So I have no idea what goes where and have been told to just start with the shortest wire first and so on but I am still confused on which run is longer then the next. Would it be helpful top take a measuring tape and go about judging which wire that way? I believe the correct firing order is 165432 clock wise from what I’m reading from other forums, if this is false then please inform me of this. Ok while standing in front of the truck the #1 would be to the right and closest to you, #5 being closest to drivers seat or steering wheel. And on the opposite side near the trucks battery or passenger side the #2 would be closest to you on your left, and #6 being closest to the passenger seat . Please help in desperate need to get this truck running right, broke and started new job and at the end of the line for help on this even autozone couldn’t tell me the firing order and they sold me the wires, wanted to slap the kid.