Hi Mike... If you could measure the depth sitting on a flat surface. Need that figure to know if the pulleys will line up. I'm thinking it may be for an AC car??
The pulley came off a Mark IV 454 that was in a 67 Impala I bought years ago. It didnt have AC but the engine may have come out of a car that did, I dont know. I replaced the steel pulleys with Billet Services aluminium pulleys when I dressed the engine for my Nova. Everything lined up perfectly.
I took more pictures that I hope will give you the info you need. I think it is the same as this unit from Summit which, according to its application, is what you are looking for.