Talked to Performance Props (520-394-2059) again, to find out what the hub thickness will be with the new prop, so I can find a spinner.  They said that they buy blanks in 4-3/8” thickness, and usually plane them down to 4-1/4”.  For Tracy’s monster prop, due to the extra pitch, they found a thicker than normal blank, and planed it down to 4-3/8”.  That’s what they will do for mine as well, so 4-3/8” is the thickest the hub could be.  This is the normal size for a 13” RV spinner, which is why Tracy was able to use his RV-8 spinner.  I’ll look at the options, and decide if I want to go with 13”, or try to find a spinner that’s 12”, with the correct hub size.   

Despite what this says, I think I ended up getting a 4-1/4" hub, though I can't find a note to that effect.  I gave all the numbers to Saber Manufacturing when I got the prop, and they sold me a crush plate, threaded lugs for the redrive, and the proper length bolts.  

Rusty