Slant 6 A Body advice. Engine and chassis.

Front sway bar first and a set of good shocks makes the biggest difference, also I'm sure your rear leafs are beat like mine, some ESPO 6 leaf springs which have a great rate will be the best bang for buck, then go from there so you can know what you'll like. I run a 1 1/8" front bar from Summit. Plenty of bar. I'm sure 7/8" or 1" should be more than you'll ever need.

Also do a search on the Moog 7103 offset UCA bushing swap too since your into handling, it will help a lot. In fact it's a key swap to get the suspension closer to modern caster handling abilities, closer to 3-4 degrees negative, stock bushing will be lucky to get 1.

Here is some light reading, check out the skosh chart half way down, and you'll see why I mentioned it:

http://www.allpar.com/history/mopar/front-end-alignment.html

And for the last consideration: If you plan on taking your engine out, and even if you don't, the front suspension pinnings can have quite a bit of flex to it, especially around the steering box, and when you install sway bars on the LCA's. It would pay to reinforce the k-member and the lower control arms. If you do a search on the topic, there are plenty of pics and methodology, floating around.

Enjoy!