What is this on my valve cover

Looks like you have a mismatch of parts. The power steering belt usually just goes to the crank pulley and not around the water pump on the early models engines. A/C and non-A/C engines use completely different brackets and pulleys and trying to mix and match can be a nightmare. Cast iron and aluminum water pump engines also used completely different brackets and pulleys too, so, you can see what a mess of a mix you can get into.
I remember trying several combinations on my hot rod 360. I had a bunch of pulleys finally got it figured out after welding 2 together