I cannot seem to find the top tree clamp for the 81-82 CB900f supersport. I tried the 750 clamp but the forks are slightly larger diameter on the 900 so it did not fit. I need one ASAP feel free to PM/DM.
39mm on the 900FIt will save you a whole bunch of grief if you just measure the diameter of the stanchion tubes in millimetres and provide that information in your parts request description, they will likely be 37mm or 38mm or 39mm forks. Motorcycle Salvage yards shop in person to get the best deals and take the old parts with you to make sure what you buy will fit.