Power steering pump

…thing where the pulley goes…you mean the pump shaft? There were two pulley depths; a more or less flat pulley used on cars without factory A/C and a dished pulley used on cars with factory A/C (with different brackets). I don't think shaft length is what's causing the pump to be cockeyed. Have a careful look at how the brackets are assembled and how the pump is attached to them; you may find evidence of a missing bolt or bent parts, etc. That said, don't expect perfection; a lot of the Slant-6 power steering pump bracket setups were kind of sloppily/carelessly engineered.