It may be 13/16". I was trying to recall...
Sounds like you're set up to go. I only suggested an extension just to get your tools that much further away from the wheel. I was trying to do the job with a 3/8" drive rachet and using the "hook a wrench on the end of the handle" trick to get more leverage. My tools were close to the tire, I slipped, and I scratched it. Bad words flew. I don't see a problem with what you have on order.
Thanks again for the info.