[pont3]

Based on my personal AC experiences I'm gonna have to agree with Wheelspin and suggest replacing the compressor and condenser and even the receiver/dryer or at least a thorough flush of the condenser. Usually when the compressor locks up it is internally destroyed and bits of metal and debris ends up in the condenser. Replacing only the compressor will lead to short life. Therefore, most remanufacturers won't warranty the compressor unless these are replaced as well. Just my experience.

[mikeb]

The compressor clutch freewheels unless the A/C is turned on, which locks the clutch and turns the compressor.

If you were driving along without the A/C on and it locked up then both the compressor and the clutch are toast. Junk and replace both.

[FWGTO]

That is exactly what happened. I was driving along with the a/c off and it locked up. I will look into replacing both clutch and compressor. Just out of curiosity, wheelspin mentioned replacing the factory screw clamps with crimp style collars. Sounds like a good idea to me, since my GTO is not 100% original (has a handful of non-build sheet changes-about 4, as best as I can determine). Are there other upgrades that make our cars more reliable, without materially affecting value, or is the question too broad for an answer?
Thanks