Rbptrsn, you have the "good" transmission (NAG1) in your 3.7. I have the same one in my Hemi LX and it's way better than the one in the 5.7 Jeep. Your tranny should normally be smooth shifting at light throttle and quite firm at WOT. Make sure the fluid level is correct and it has been serviced at the proper intervals. Mine will snap your head off on the WOT upshifts. For giggles you may also want to check the throttle body too and make sure there is no contamination, especially the back side of the throttle butterfly. I haven't heard of any of the 3.7 folks having this problem, but that doesn't mean it can't happen.
2000, on yours, a few preferences that I use on mine, FWIW.
--I have had good luck with NGK copper plugs, LZTR4A-11, Stock No. 5306. The Hemi takes 16 plugs. Never had an issue with either of my Hemi's.
--As said before, a good synthetic oil seems to work better than a good dino. oil. I use Mobil 1 oil/filter at 6000 mi. change intervals. Some change sooner and a few change later.
--On the air filter, I have a K and N in the LX and a TruFlow in the WK. I think, between the two, I like the TruFlow a little better. It seems to filter a little better. Just my opinion only though.
--I don't recall the cabin filter install being any big deal. I know I didn't remove the wiper though.
--IMO, with your mileage, I think changing the EGR, PCV and and MAP would be good. It'll let you know where you're at for future reference, and may preclude some problems down the road. All 3 should be under ~$100.
--Again, IMO, the trans. service, like Walt said, is a must. Look for any debris on the magnet and/or in the bottom of the pan. Fluid will probably be brown (OK), but not burnt smelling. Main issues here have been...bad return filter (TSB) and side splitting on the main filter so it sucks air. Also, on reinstall of new filter, be sure to follow instructions in FSM to make sure it is properly seated.
--Definitely do the Xfer case and diffs. Fluids are a little spendy, but a lot cheaper than new parts. Again, then you'll know where you're at with regard to the maintenance status of the vehicle.
--Yep on the serpentine belt. I carry the old one as a spare, just in case. I also carry a cam and crank position sensor in both Hemi vehicles, as an on road failure of one of them could possibley leave you stranded. May never need them but, again IMO, it's cheap insurance. I hate breakdowns.
--I am not a big fan of the cleaners that you run through the engine. Fuel injector cleaner is probably not as bad as some of the other stuff though. That being said, with the Hemi's lousy crankcase ventilation system, it may be necessary, depending how bad your throttle body and intake plenum looks. All the contaminants end up going out the exhaust and through the O2 Sensors and catalytic converters, possibly shortening their lives. See the thread I did on O2's: http://www.jeepforum.com/forum/f67/o...rimer-1182446/
I stay away from those cleaners like the plague. Once you're on top of the maintenance and use good quality fuel, there really should be no need for them anyway.
Hope this helps a little. Good luck on your maintenance quest, and let us know how it goes.