Going to use @AlbertoSD excellent write up on how to install the boost compensator.
1985 BJ70 Story and Modifications
Just subscribed to your thread, David!
Glad whatever I write can finally help somebody

Please feel free to ask questions if you have any. I did the Boost Compensator fairly recently and I dreaded it more than I should have. It was actually pretty easy, specially if the engine is out of the truck.
I have to read the whole thread with detail

This is a great project and I am happy to see you taking it in this direction!
-Alberto