Turns out the tranny was an easier fix than I thought. A regular U bolt wasn't long enough, nor had the right ID, but going through the McMaster Carr book I found a slightly larger ID with a longer shank. It was also a beefier 3/8" than the stock 5/16.
I used a die grinder to slot the shifter mount and increase the radius, I had to bend the u-bolt a bit more and use a flanged and lock nut to make sure it doesn't come loose.
A few adjustments and it shifts fine. Hope to install Sunday since Saturday is race day at Road Atlanta. Gotta get some ideas for the track car.