I think 33 inch wheels would work fine on that car too. And would require probably a little less shim.
I have converted a bunch of the PS series cars and a couple of stock cars. I really ilke the PS gons and flatcars. I have ot stumbled onto to very many of the boxcars.
I have also converted a long string of the GLa hoppers.
I often use Athearn wheelsets in my conversions. the fit is a little sloppy but on the older trucks with stamped bolsters, you can squeeze the bolster in a bit and get a good fit. In either case they roll well.
The GLas came with screws and holes drilled for Kadees and shim plate. On the PS cars, I just line it up by site and drill the first hole. then mount the box to locate and drill the second hole. On the flat cars, I use a contact glue to glue the box on since there is not much material there.