After some time of tracking down this problem, another post pointed me in the right direction. I knew the problem was the torque converter going in and out of lock up. It would do this around 45mph while in OD and the cruise control set. I would start going up a hill and the cruise woudl start adding power, but not enough to down shift. I would then get a surge. Every now and then I would get this in the city around 25 to 30 mph. I played around with the tune but never was able to remove the problem.

Turns out the fix was simple and cost nothing but some time. I made a write up on this.

https://www.gmforum.com/t284972/

If you don't want to go threw all the testing and just make the adjustment, that'* easy. The top switch is what you want. Twist is 1/8 turn CCW, hold it in place, depress the brake pedal just enough that you feel the switch move in. Twist the switch 1/8 turn CW to lock it in place.

After a few days of driving, I have noticed no surging.