Cheap handeling upgrades for 67 cuda

OP you did not tell us much. Is this a slant/ v8, what? Originally such?

"Let's say" it is or was a slant..... just a blue sky example. This means the torsion bars are tiny noodles So ONE simple cheap upgrade is to simply find the heaviest (largest) v8 T bars you can find.

As said above---get a helper and find out what's loose. Have the helper move the steering wheel at various rates and distance back and forth while you look CAREFULLY with a big light. Look for play between two adjoining parts

The steering column coupling, look for play between the upper shaft and the coupling, then for play between coupling and the shaft into the box. Look for play in the box bearing at this shaft

Go under. Look for play at the pitman shaft up down and side to side in the bearing. Watch the coupler move and watch how much delay/ play between it and when the pitman moves

Look for play between pitman arm and ball joint connection to the center link

Look for up/ down / any other play in the idler arm. Look for play in each of the 4 tie rod ends

BALL JOINTS READ the shop manual. You MUST jack up the lower arms so the arm is supporting the weight and the lower ball joint is unloaded.

Bushings. "Just assume" they are bad unless things look newish or that you have history they have been replaced. A crowbar helps, but bushing can be difficult. They can be "pretty mushy" and sometimes feel good. "I would just plan" on replacing them

Go to MyMopar and download yourself a shop manual. You may or may not have to satisfy yourself with a Dart manual instead of Plymouth, etc. READ the front end/ steering related sections

Anti sway / roll bar. MOST of these lower end non performance cars do NOT have an anti-roll bar and SHOULD Various approaches to that. ONE OF THE SINGLE BIGGEST improvements on my 67 Dart!!!!
ALIGNMENT.......Can make a huge difference in handling. You do NOT want factory specs using radial tires. There is a "skosh chart" floating around from All-Par which explains that

Turn of the screw: front end alignment for performance...
Last, tires and shocks make a tremendous difference