What year PCM? If if it JTEC you can use SCT. You can buy a handheld tuner and pay someone to tune or buy a proracer package that lets you do everything yourself. I bought the PRP+Handheld for $250 ... the MSRP is $1000 .... sometimes deals can be had on this stuff.
Here is an example of what the PRP can do, I am meangreen BTW:
http://www.dakota-durango.com/forum/showthread.php?t=47498
The learning curve is steep though, so if your not a DIY type guy you can pay someone to write you a tune for about $150
I also used an Accel DFI setup on the same truck. That was a million times better, but more expensive and wasn't smoggable on my truck.
You will need datalogging with the SCT setup. Shoot me a PM if you go either of these directions and I can give you a hand setting up a base tune ....
