First, you don't need to drop the cats to replace your trans pan and/or connector sleeve. Second, I have not replaced the manifold or gaskets, however when I worked at JC's British I followed my fellow technician as he did a set. What I learned is that you can maneuver them out where the cats sit when they are removed. For access to some of the manifold bolts you take the heat shields out of the fender wells (little aluminum pieces that fit together so they can be removed easily. I am not positive if he raised the engine (same trick for doing the trans pan) to remove the manifolds. You take the 13mm bolts out of the top of the motor mount, disconnect the intake hose to the air filter box, take the top fan shield off (all of which allow you to raise the engine). I have used screw jacks with a lift, but am certain you could use a couple floor jacks and some blocks of wood. Place a floor jack with wood under the driver side of the vehicle and place on the center diff just enough to lift the diff and remove the 18mm bolt to the center diff mount. Then run a floor jack under the front bumper and assuming you have removed both skid plates add wood and place under the oil pan. Alternating between both jacks raise the engine to clearance the trans pan. This process may come in handy for the manifolds as well. Only do one motor mount at a time and be careful lowering the engine back down. Leave a few mm before setting the engine on the mount to give you adjustment space to get the bolts started. I also add a little blue loctite to the mount bolts just to help secure them.