That rear dump drivers side manifold was never used on a CJ (or a Wagoneer w/manual trans for that matter). I doubt you'll find enough clearance to use it.
All the exhaust manifolds are 2 1/4" at the dump. My CJ uses 2 1/4" pipe for each side, then 3" from where they meet to the rear. I run the CJ driver side manifold that dumps on #5.





Bob
tufcj