I am almost finished with the switch to a 3.2. Here are most of the things you will need:
1. 3.2 ECM (engine computer). Continue using the 2.7 ecm at your own risk. These engines are different and require different fuel flows, timing, etc.
2. The power steering pump is different, and the PS reservoir is located off the pump. Need the pump, reservoir, a pressure line and a return line.
3. The a/c compressor is basically the same as in the 2.7, but the manifold and a/c lines that run to the firewall and the condenser are different. Alarkyokie (another member who also did the switch) was able to bend the existing a/c lines and still use the 2.7 compressor, but I know I would end up quickly crushing the tubing if I tried it.
4. Need different radiator hoses to and from the radiator.
5. Need different heater hoses ( the hoses that run to the heater core ).
6. The catalytic converters and exhaust pipes can be reused, but the passengers side will require that it be shortened 3 inches between the oxygen sensor and where the pipe starts to bend downwards.
7. Need different alternator.
8. One of the motor mounts is different. The aluminum brackets that mount to the engine block and attach to the mounts are different. I got very lucky with mine because the junkyard left the brackets and mounts on the engine. These are almost always thrown in the trash when they take the engine out.
I think that covers most of it, but I may have forgotten something. Please feel free to ask questions - I would be happy to help. There are other members out there who have done this and have been very helpful and supplied me with valuable advice. Also, there is a link you might want to browse: click me.