Gentlemen, My name is Tom DiLascio, President of Imports Only, Inc. I have a customer who purchased new a 73 164 sedan and "still" owns it. Problem I am having with this vehicle is either with the P/S or AC. The compressor and p/s operate off a common belt. When the AC is turned on, a bad vibration is felt throughout the car. The AC compressor is mounted by fabricated steel brackets (no rubber bushings) The noise is coming from the power steering. I can literally watch the pump/hoses shake. The steering is the same with our without the AC on. Problem does not occur until the AC is turned on. He does not utilize the AC because of this vibration. I suspect the fact that the compressor is bolted directly to the block and the compressor to the brackets making for a solid mount. When the compressor clutch engages, it passes vibration through to the p/s pump as it is driven by the ac. This is a quess. Any suggestions would be greatly appreciated. Thanks in advance to those who respond. Tom