I have been looking at doing 180's for a long time while planning my build. I have saved about 125 pics of various cars with these set ups from the forum here as well as other places on the net.
If I were to build them I would consider doing a flange between the right and left so you can bolt them up without slip joints.
Also it looks like most people don't have any muffler supports. I would think this would lead to cracks. I was planning on a muffler support bracket using the trans mounting bolts or something.
Now this is nul and void as I am leaning heavily to go 5.0L modular.