I'm using a C5-based front suspension in my 240-Z project. I built a full spaceframe to mount it and had to widen the car's fenders about 10'' as noted above. Now, if I could only find some time to get back to work on the darned thing!
http://www.geocities.com/boodlefoof/Project_Racer-Zsuspension3.html
I think tube80z's comment is directed at the ladder frame picture posted above. Without a rigid frame to mount the suspension to, it cannot work well. Since the ladder frame has no designed-in resistance to twisting forces other than the strength of the metal used, it will not provide optimal suspension performance. Likewise, the unibody construction of the Z can be improved upon as far as torsional rigidity.