I've heard of people flipping the gear but I decided not to try it and just bought a new one, they aren't expensive I think mine was $20. The ring gear also has a small bevel on the inside that goes against the flywheel.

I’ve flipped the starter ring gears on standard trans flywheels without issue but if a new ring gear is available and time is not an issue, then by all means purchase a new ring gear.  If flipping the ring gear on a V8 flywheel, then be sure to clock it 45° different than where it was originally so that the new side being used is contacting a fresh set of teeth.  You’ll find starter wear marks each 90° on a V8 ring gear and 60° on a six cylinder and you’ll want the reversed ring gear using a unused section of teeth.

Lorena, Texas (South of Waco)

Installed the heavy gage battery cables today (made by NAPA).   The engine turned right over (with the original starter) in it.  So now I have the brand new starter that I will keep,  just in case.  Cable size was the fix.  When I started to dress up the engine compartment, I started replacing battery cables.  They were lighter gage......no good.   Thanks for all the help and ideas  

Have you tried a known good condenser? As mentioned in the other thread the new ones, are not specifically too good.