ladder bars

to answer your original question...I think a 36" with a 8" instant center would be a good place to start.

you might want to take a look at my homemade parrallel 4-bar/4-link I put under my silver Duster. I run it as a parrallel 4-bar for street cruisen...but if push comes to shove (drag race trim)...it can easily be re-configured to a 32",36" or 40" (ladder)bar with a appx 8' instant center.

kinda the best of both worlds....already put 200-plus cushiony miles on the parrallel 4-bar...this winter i re-configured to the 36" set-up...just to see how it acts...and replaced the poly ends with the ride-tech rubber bushed ends...on the housing part anyways

lots of pics on page 2 (parrallel set-up) and page 67 (36" w/8" center 4-link) of my build thread...A bodies/Big motors..new Hemi Duster final assembly