Concours rear wheel on 1980 Kz1000

I recently purchased a 1980 Kz1000 and the previous owner has adapted a concours rear wheel to chain drive. I need to replace the bearing on the drive hub but have no idea what it is off of. It is running a 630 chain with a 38 tooth sprocket. If anyone has a clue as to what this setup may be the info would be greatly appreciated.

You may have stumped us...a picture might aid greatly, but you might have to knock the bearing out to see what it is:(

the bearing type and number will be on the seal in the bearing look for a 4 digit number like 6205 something like that. the seal will have the measurements on it as well

Thanks for the replies. I ended up just taking it to the dealer. They had no clue either but were able to match the bearing and get it repaired.