I'll be installed a pair of 383 torsion bars - MP# P5249150. This is a trade-off. The best springs for drag racing are 6-cylinder bars, but they're rotten for handling. A friend had the 318 bars in a Duster, and those weren't much good, either.
I also installed an Addco anti-sway bar for the front. It's 1-1/8" which is pretty big. The bar is for a '73 and later car, which matches the k-frame. The '72 and earlier bar runs along the front of the k member. The '73 and later bar runs through the k member. The '72 and earlier bar is longer too and the brackets ion the LCA's are further out. I made some mounts for the lower control arms.
Bill Reilly at www.reillymotorsports.com makes some nifty suspension upgrades. I bought the tubular strut rods and tubular upper control arms. The upper control arms move the upper ball joint back slightly to give increased caster for better stability at speed and less tendency to wander. The tubular strut rods replace the rubber bushing with a ball joint rod end (or Heim end). You can see them in the photos. These prevent the lower control arm from moving fore-aft by compressing the rubber. I think they'll make a big difference.
I replaced the lower control arm bushings with rubber replacement bushings. For details click here.
The front end being taken apart. The anti-sway bar on the floor is the '72 and earlier Addco bar.
Upper control arms. These came apart very easily, thanks to my dad, who took them out in a junk yard years ago. It also helps that the car was garaged for many years.
Here's a comparison of the stock strut rods next to the tubular rods.
A tubular rod in place.
Here's Bill's original design, where you thread the stock rods. It was very difficult to get the die to travel straight. By the time you get an inch of threads, the die was hardly cutting on one side. The stock rods were 5/8 diameter, and you needed to thread them to 5/8-18. Next to it is the tubular rod - a much better arrangement.
Here's my original setup for the anti-sway bar mounts. It didn't quite have enough travel.
The new design. This has more than enough travel. I used a beefier heim end too.
With a stiff anti-sway bar, word has it you should use a reinforcing plate on the lower control arm. I could have bought the really nice, laser-cut plates. Insead, I made my own crude, but effective, plates.
Here is the plate tacked to the control arm. The holes are needed for adjusting torsion bars and for drainage.