I run them in mine with a single shackle and wish I'd run the double. They are a pretty flat spring to start with so without an add a leave you don't get much up travel before the spring goes reverse arch. You do get a lot of droop though with a double shackle. Just make sure you run a bumpstop and an extended brake line. Like Dan said they do give an awesome ride.
85 Flat deck toyota, chevy's, new frame, for sale.