There is no problem using a 10" disc in your case.
In 1954 Chev cars with the standard option clutch had a 9" disc with a 10" pressure plate. If you ordered the HD option they installed a 10" disc.
I put smaller discs in all the time as they have less of a chance for clutch chatter.
The only reason to go as big as possible would be if you are planning to haul heavy loads.
