Do you have the V6 or I4?
I thought the V6 MX6 always came with AC, so you had to ask for the belt for a Probe V6 without AC. Maybe I'm wrong, or maybe you have the I4.
Edit: I just checked on ProbeTalk, and for the V6 you need the "340K5" (if it's a dayco belt). So I think that's the right one. (The "K5" means 5 ridges in the belt, and the "340" means 34.0 inches).
By the way, you don't need to remove the AC pulley. The belt will fit without removing the pulley. To reduce weight, remove the whole AC compressor. Check the thread in the Probetalk performance V6 archives.
I thought the V6 MX6 always came with AC, so you had to ask for the belt for a Probe V6 without AC. Maybe I'm wrong, or maybe you have the I4.
Edit: I just checked on ProbeTalk, and for the V6 you need the "340K5" (if it's a dayco belt). So I think that's the right one. (The "K5" means 5 ridges in the belt, and the "340" means 34.0 inches).
By the way, you don't need to remove the AC pulley. The belt will fit without removing the pulley. To reduce weight, remove the whole AC compressor. Check the thread in the Probetalk performance V6 archives.