I built a triangulated 4 link in my 73 Cuda, my top bars go from mid axle to the center of the rear floor pan. There isn't a lot of room on the E bodies either but I made it work. I will say this, with a triangulated 4 link you do not get a lot of movement up and down especially with short bars, that said you do get good handling as that rearend is not going anywhere. I did a lot of research on this when I was in the planning stages of the car, I decided on the triangulated 4 link for handling, if I was building a drag car I would have went parallel 4 link.
Now just to get this out there; I am not saying that leaf springs don't work, in fact I know they do, however I wanted to do the triangulated 4 link "just because". I had never built one and wanted to do it, also at the time of planning I was leaning towards a road race car (changed directions along the way to more of a street car that handles like a road racer). If you are committed to a 4 link for whatever reason, a triangulated variant is preferable for a street car that you want to handle IMO.