Get rid of the J bolts completely. Or throw them in your 'spares' or 'trail' bag.
Get 4 flange nuts 3/4 size drill a hole in the bottom of the frame. Weld in the nuts. Now all you have to do is take out the four bolts and do your t-case maintenance. Also, the skid plate will not shift when you go over rocks.
Have had mine that way for 10 years plus, and no problems (knock on wood)