You might do a search on here. Why are you wanting to add them? The stock rear rudders are ok for flying but there’s no way I could be safe landing in any adverse conditions with them. It’s hard to explain but they feel clunky and unwieldy. There’s no ‘feel’ to them. Others may have opinions but I would highly recommend the upgraded custom ones that others on here have created. Never flown the custom ones but the geometry looks much better.
I’ve only flown a tailwheel plane with them but it was dangerous (for me) - more accomplished pilots may have a different take on them.