66 barracuda 273 power steering

RedFish said
That setup shows a 3rd sheathe/pulley so its for a/c even though there is no a/c belt on it. The p/s sheathe bolts right in on top of the first sheathe with the same bolts to balancer. A later model p/s sheathe will work but one bolt hole will be in a slightly different position. Easy fix with a rat tail file.

That third groove is a bolt on aluminum pulley. I’m not sure why it is there as the car is very much untouched original configuration. I believe the car is “dealer prep” for aftermarket A/C (knee knocker)as I stated before. I’ve not seen an
aluminum pulley on a car before unless it came from an after market ac shop that were popular in the 70’s. Even the bolts holding it down are off the shelf bolts not the Chrysler 5/16” bolts typically holding the pulleys to the balancer.