Mr. Jay,
I agree with Jerry, you do need to harden your shift shaft. Not just the ball area but the end that will be bolted to your shifter lever. I have a Hurst shifter but I modified the original
shifter lever to be fit the shifter. It looked like yours. As I shifted from left to right/right to left, I could feel it give way slightly to it felt like a bend. The shifter lever wasn't hardened so it was going to eventually snap. I had the
shifter lever redone/shortened, reinforced, and hardened. It is good to go now.
Your shifter set up is the opposite of mine, to where you modified your shifter at the ball and lever connection. The metal is weak on both ends.
Just my 2 Abe Lincolns,
Bread
.