Sorry, just noticed the message.
Correct, 1" would be the shaft size.
Whether to change props depends on your goal. Are you looking for more boat speed under sail? Higher RPM while motoring? What's your engine RPM at cruising speed? RPMs at top speed?

I have a 3 blade 12x6x 1" 3 blade cal 29 I'm thinking of going to a folding geared GORI propeller . I am assuming the 1 inch is the shaft size? Any thoughts or recommendations?