Upgrading front suspension in my 64 cuda
I'd suggest Firm Feel tubular upper control arms for extra positive caster without using the offset upper control arm bushings. Add Lower control arm reinforcement plates, roller bearing idler kit, 11/16 tie rods, Moog lower control arm bushings, Have Firm Feel rebuild your manual box (it will be better than new plus they can swap 20:1 or 16:1 ratio again), new pitman arm, I love my Bilstein shocks (but have only run KYB's and regular gas shocks). Now for the cheap part, find a set of .88 diameter torsion bars (minimum) and get a set of "A" body 4 speed leaf springs or a set from an "A" body station wagon, they should have 6 leaves. Factory early sway bars are good, but use a front bar. Get a real good front end guy and treat him right, he is the most important part of what you want to end up with.
Brakes, figure out whether you want large or small bolt pattern. 73-76 brakes are great, but what are you going to do with the rear? The 8 3/4 rear has the best bearings for cornering, the OEM tapered. So, now I'd get custom axles and housing to convert to the big bolt pattern and keep your track centered in your wheel wells with stock offset wheels. Or find a set of K-H small pattern discs and run the stock 8 3/4 "A" body rear? There are lot of other choices, but these are it for me.
Next comes wheels and tires. I like U, V, and Z speed rated tires with a tread wear of less than 300 A A. They can be found in 15 inch sizes, pretty hard in 14 inch.
The difference will be night and day.
One suggestion, I'd rebuild the pushbutton 904 to hold the 360 and get a B & M flexplate to balance it for the 64 Cuda. I always loved the pushbutton trans.