Several years ago, I ran across some guys that had lowered "slabs" and they did it with a 4-link rear suspension. They had extensive pictures on the website I found. The ease of doing it was quite interesting! Using existing rear "frame" areas to do the whole deal.
The question I might have is "Why?" What can the coil-over set-up do that can't be achieved wit the existing leaf spring design? Just curious.
One of the key things in a "link" rear suspension, whether a stock GM-style design or otherwise, is the lateral location rod's location and "arc of movement". As close as the clearance between the tire and quarter panel can be, as is, this lateral movement might become an issue.
The one real advantage I can see in the "link" design is getting the leaf springs out of the way for monster backspacing wheels and tires. But then that'd also mean new wheel tubs at the back, too. Again, "Why?"
Seems like the guy that had the website did it on a '66 Newport 2-dr hardtop, in basic black satin? Probably in a Google search?
The ride characteristics of a coil-over system are definitely different than either an older coil spring suspension or torsion bars and leaf springs. The theory might be the same, but the actual dynamics are different.
CBODY67