Um, well the one that uses the shackle mount is for an XJ, so, there's zero chance that would bolt up to an A-body. You'd have to fabricate something that would work, and I really don't see the point on an A-body. If you're fabricating, just make it bolt onto the location where the shackle mount bolts on and reduce the redundancy. Either way you're making something.
And here's the thing, the stock shackles work ok. Leaf spring sliders are neat, they work great, they take some flex and bind out of the system. But on a street car they're not a modification you do and go "wow, what a difference!". They're a modification you do once you've already optimized everything else, and they're not something you're going to notice unless you're competitively running against a clock. And maybe not even then, depending on the rest of your set up. Using a set of shackles with some well greased poly bushings will work pretty well for a street car. Sure, the sliders are a little more efficient, but they're not some "must have" deal.
