you can drop an 46 RE into that truck directly, same driveshaft, same mount, same wiring as long as you get one from a 96 to a (I forget which) either a 99 or Y2K truck or van..... I know that 01 is different, but I also know that the transmission aftermarket has what it takes to make the 01 and newer 46RH backwards compatible. all wiring and plug in related....

 

Yep, in 00, Dodge changed the sensor in the trans, and a retainer. Of course, all the internal connectors changed as well, but, its a simple matter to swap out the electronics for the older versions, just need the correct retainer.

 

If you really want to do a build, get great hp, tq, and still get good gas mileage.....
id honestly reccomend swapping to the hemi and 6-8 speed transmission. If you do your research and searching you can find a truck that's been totaled and pick up the engine, trans, wire harness and ecm for a fairly decent price. Building engine mounts, and trans mount isn't all that hard if you're good with a welder. If you buy an aluminum block hemi from a car you can drastically save on weight which helps with launching from a stop as well as stopping, however the cam and heads between the car engines and trucks are usually different. Truck engines usually have more torque and that torque is lower in the rpm range.
Personally I think alot of us Dakota guys would really like to see a well documented budget based hemi swap. I know people have done them but it's usually people with alot of Money to spare and they dont document the build or post alot of pictures.
Btw the ecms on the hemis will have alot of options built Into them that you won't be able to use on your truck but a hp tuner, software, and a laptop/PC will allow you to turn off those options so the engine will run