I read you are thinking of running an MS112 crown diff in your RA40. I had such a diff in my Sprinter for a while (out now due to some other problems) and getting wheels to fit was a bitch.
5 by 114.3 is common, but the Crown centre bore is 67mm, and so most factory wheels wont fit unless you have them enlarged.
AU onward Falcon wheels fitted OK but being a minimum of 16" they were simply too big for me. Another option are Magna 15" steelies. Maybe something to get started on before buying a nice set of wheels.
Aftermarket wheels apparently always have big centre bores, so they shouldn't be a problem.
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