The ACDelco site is down, I looked there for info. Personally I used the 746BB on my car and my dad's, the high dollar wire craze is just hype. Do you have a local dealer you could go and look at these wires? They may have both or just the newer in stock? Worth a shot. For what it is worth, I went with the Iridium plugs also. I bought the slightly cheaper ACDelco platinum, but when I pulled out the 107K mile iridiums,I jumped on my bike and went and got some more. They looked awesome, and i plan on keeping this car until 200K. Have fun changing the back plugs. There is a secret that helps. Park car on slight hill so front of car is down hill, disconnect the top engine mounts, leave car in park, push on door frame, this rocks the motor forward, put on E-brake. I moved the engine 2-3" and that made it 200% easier.