There are 2 different valves . Weather Head found on most 73 and newer A-bodies also B-and E bodies with single piston brakes. Then there is the Kelsey Hayes style used with 4 piston caliper 70-72 brakes. 69 and earlier have a separate valve for 4 piston Disc brakes.
as far as the new replacements, all I've ever seen are the weatherhead style (which mine is in the original post). the site you posted is where I would going to buy a seal kit from until I found how badly the valve in the original post was pitted.
