I ran a homemade bar on my rockcrawler like the one in this link. The rig had long flexy leaves mounted above the axle, a SBC, SM420 trans and 5.29 gears. The first time out in the rocks just messing around before the bar was installed, the leaves wrapped enough to actually snap off the rear pinion gear at the pumpkin. After putting the bar on I ran that rig for over ten years without another wrap problem.
http://www.chassisunlimited.com/prod...n-bar-kit.html
Edited to add: Forgot to mention that we made the shackle end of my version reverse from what is shown in the link with the frame mount at the bottom of the shackle and the ladder mounted to the upper part of the shackle. That way when the front of the bar tries to lift under acceleration it can't since the shackle is a fixed length. You also wouldn't need heim / johnny joints like the link since it's designed for offroad articulation. Urethane bushings would be fine.