I have done it with 3 factory stocks. I used 1/4" all thread and JB Weld (because that's what I had laying around).

I cut out the molded in pieces in the stock so I could lay the all thread from in front of the lug to the swivel stud. I then drilled a series of 1/8" dimples in the stock channel just to give the JB Weld some extra mechanical looking points. After that I proceeded to start laying in the JB Weld then pressed the rod in and finished covering with JB Weld.

I usually let the JB Weld set and harden a little but for this application I prefer it thinned out so it runs into any voids.