The reality is it isn't, very old school operation, quite small.
They have a few tricks for layout.
(I have seen their shop, it was after that post)
Alan
The ACM-6056 is what I recently put on my CHP project. The mufflers used on the CHP cars were not standard C-Body mufflers, they were Mopar muffler but not necessarily the Hemi ones.
Alan
From the factory these cars did not have exhaust manifold gaskets. Over time with heat cycling things may change. They do sell gaskets now for these, it would not hurt to install a set.
Alan