Car has the old leaf springs and old air shocks. Idk what parts would be the biggest bang for the buck to get the rear feeling good. Example,, new leaf springs,,,from which company, multi oe style or singles.. Shocks ,,, brand and style. Are coil overs an option or not without doing a lot of work? It is a street car with good hard power and handles like a crow foot bathtub in the ocean during a cat 5 hurricane. The front has old shocks as well. Who has good shocks that don't break the bank? Thanks.

Any help?

This thread should have some useful information:

https://board.moparts.org/ubbthread...handling-mods-and-hints.html#Post3120113

I'd suggest an adjustable 1-2 way shock if affordable, and since we don't know your tire package for street everything is a wild guess.
Resist the temptation initially to add a rear sway bar, that is much later in the process.

How much money do you have to spend?
If you provide a real number for a budget - a parts list can be developed to start the building process.
Without a realistic number this is just a conversation around the campfire.

Also, is this a car for twisty roads, road courses, drag strip, or cruising ?

Lol, I like campfire talk. Great ideas comes from that. I’d like to stay in the 1500 range if possible or less.

The car is mostly driven on curvy country Roads

Given that and the budget mentioned the stock suspension is more than adequate. Tires will be the biggest bang for the bucks.

Some might suggest some sort of "improvement" but if you update the rear without updating the front too then you'll have an "interesting" ride. If you update the front as well you blow the budget.

Figure out what tire would be best, what the budget is for the 4 of them then that will leave whatever is left for the rear suspension. Priority one is getting rid of the air shocks. At this point you will likely have hit your budget limit. Probably go over it if you have 14" rims right now, no "good" tire in the 14" rim size. At least not one that would qualify it as belonging in this forum anyway.

What rims and tires does the car have on it now? Does the car have sway bars? Any remotely modern 15" radial tire (even BFG T/A would be acceptable), matched front and rear sway bars and something like Monroe Sensatrac Shocks. You said winding country roads in another post. The sway bars will be a dramatic difference right there without effecting ride comfort.

Yeah, more tire, likely wider wheels - basically, fill the wheel wells - and air shocks are usually a band-aid for dead rear springs.
If all the bushings are 56 years old, they're probably "done".
Rear spring rate should work with ft t-bar rate - ESPO is who I'd use on a street car.
Bigger ft sway bar & added rear sway bar will control body roll, as will increased spring rates, depends on desired ride quality & how the car is driven.
Decades ago, I had a Satellite wagon, and with a sound but stock suspension, doing sway bars hugely improved the handling but retained a pleasant ride quality.
It was surprisingly pitch-able for a big tank, but of course it wasn't like a sorted pony car; yet it was stable & predictable.
Pretty easy to burn through $1500 nowadays, unless you get lucky with good used stuff.
Really need more specific info on condition, what the OP already has, and a more specific goal.

All good info...surprised no one mentioned frame connectors. One of THE best improvements I did on mine....and CHEAP if you can weld or know someone who can. I have a 69 w/ a BB. Stock frt(disc conversion) and rear with larger t-bars up front and SS springs in back. Front and rear sway bars from Hellwig and BFGs. It's not a corner carver but it handles firm and very predictable. Works great for me