I doubt that will help.  Too few and on a discontinued engine.  I'm like Scott and sticking with the stock manifold.  I should replace the downpipe to route it around the oil pan instead of over it though.
Problem for me is that the Thorley so far is one of the best performance mods I have, 
Switching from the stock to it was night and day on power and mileage, literally gave 
me a gear back on a hill on my commute. Mainly in the torque department...
Besides, after buying 3 of the stock manifolds in 2 years....
If I had it to do over again I would season the manifold 
thoroughly before installing. 
( Heat the manifold up to 600+ and keep it there for a while then let it cool down slowly over several hours... )
My current pipe runs under the tranny just behind the bell-housing. I did see 
one that ran down and around the front of the oil pan though. Which if there 
was room to fit the cat up there would be sweet , should put less heat into the floor of the jeep.
I've been practicing, I'm going to build another header based on the 
thorley design but with some changes 

Dave