Awesome! I have a 78 II that I am right now in the process of putting on stumpys bars.
And I like your Idea of the laser cut blocks that you made but on mine, I simply put some wedges on top of the those spring cups to maintain the pinion angle and then the one inch block and I rely on the U bolts to hold everything in place.
I am new to this site but I will be posting pics of mine soon!