With ladder bars and leaf springs, the rear end housing must be mounted in "floaters" in order for the leaf springs and ladder bars to work without binding.
If you do not have something like this :
http://www.competitionengineering.co...?CatCode=10047
on your car, and you're running ladder bars and leaf springs, your rear suspension simply does not work.
Given the choice, I'd never bother with ladder bars again, ever. If I wanted full aftermarket rear suspension, it would be a four link with a wishbone locater and coil over shocks.
For a car like yours, if you do not intend to go faster than 9.30 or so, and you want to run smaller tires, say 9" and 12" slicks, the by all means I'd put a complete Cal Tracs system under it, their leaf springs, their bars, their mounts, and their shocks.
Sure, full aftermarket suspension is the ultimate, if it is allowed, and you're going really quick, it's the thing to have.
But you're running in the mid nines, and you're running 9" tire classes at times. I would not go to the expense of a four link for that.