Putting complete V8 Suspension under 74 Dart, what all to have before swapping?

Go with a Helwig anti sway bar or other well designed aftermarket unit. They are a few more bucks, but engineered much better.

Addco bar is ok, but their mounting system is less than substandard, and will fail at some point. Don’t waste money and time on one.

I would look for new torsion bars in the 0.940” to 1.00 inch range, a decent set of shocks front and back, all new bushings with tight serviceable suspension parts, and you will have a nice handling car.

You should consider installing a set of sub frame connectors as well to tie front and rear of car together.