hello collective wisdom

I have a question regarding if the clutch that is in an aircooled vanagon is indeed the same clutch that is in the 86-91 watercooled vanagons or were they upgraded. i have access to a couple clutch kits that he tells me are for aircooled vanagons and thinks  they are the same ones for the 2.1 but is not 100% positive. (he owned a shop that served mostly the air cooled crowd). I'm doing the subi conversion and might as well swap out while I'm in there. all I know is 228mm

does anyone know?

thanks in advance

mike