Mounting factory GM 2nd row seat belts to roll cage

[My3Sons!]

I have 2nd and 3rd row seats from 2011 Escalade in my 71 Jimmy, and wanted to install factory 3 point seat belts for the 2nd row (my front seats). I'm looking for anyone who may have done this and could share any pics of how they fab'd it up. The issue I'm trying to overcome is when just holding the seat belt assembly by hand, it has to be at a precise angle in order for them to retract (well, the opposite of retract). There is a little ball bearing that falls to lock it in place, has to do with the auto lock via inertia. My assumption is that if I can get them bolted up at this precise angle, I should be good. Anybody tackle this already?