HRD,

Couple of things. 1st, I picked up 1mpg on my 2wd 318 auto long bed dakota just by installing a soft roll up tonneau cover. Not and engine mod, but $300 well spent.

As far as intake temps, I have a 2002 Ram 1500 van. I did not like it running on the ragged edge of overheating, so I installed a dual fan set up out of an intrepid. Plenty of those out there available for parts. I also installed a flea bay a/m all aluminum 3 row rad. Cooling temps are down from 205* to 180* on all but the hottest of days. Probably not as big an issue where you live v/s Atlanta.

Magnaflow makes a nice y pipe for our trucks with mandrel bends and bolts up directly to factory exh manifolds.

Another area for easy improvement for automatics is a shift kit along with a good a/m converter. OEM converters are not as efficient as a good a/m with custom full welded vanes and bearings v/s bushings.

Lastly, you might watch ebay for some doug thorley/mopar performance tri y headers for your truck. I have had good luck finding them. As long as you are not in a hurry they do pop up from time to time.