Suspension upgrades

there are a lot of ways to get where you want to go. you can drop coin an aftermarket BBP disc brake set up or you can swap everything over to the 73~76 style or, you can use some of the parts from your original set up but you may run into some fitment issues-- namely caliper to sway bar logistics-- but it's all surmountable.

personally, for what you're trying to achieve I'd just swap everything over to the 73~76 style. it'll be cheaper, easier and it's kind of a known entity. get a bigger sway bar, bigger T-bars and some decent shocks and you're pretty well set from there. out back, I'd upgrade the bushings and add a small sway bar. if the springs are still good and don't exhibit sag, I'd run them. if they need replaced I'd go with something that the rate compliments the T-bars-- just not SS springs.

what kind of budget are you working with? do you want rear disc brakes? are you okay with manual brakes or do you want or need power brakes?

just remember, you don't *need* $1,500 disc brakes and you don't *need* 1" T-bars and tubular adjustable control arms to make these cars handle quite well. you can accomplish quite a bit if you decide what type of driving you want to do and build it out as a system rather than just throw parts at it wholesale.
I have 20 to 25Gs to spend. That would include new heads for the engine, as well as other goodies like aluminum rad and electric fan. I realize I will not get the money back out, but that is not an issue, This car will stay in the family. I am not doing the work, having a shop work with me here locally. Sounds like if we rebuild the front end using better parts that are in there will probably do the trick. Discs upfront for sure, maybe rear too. No auto cross or any of that, just want a good handling and stopping car that is reliable. The replacement 340 has had some mods done and is ready to go, and will be swapping parts from the old motor to it. My air gap, carb, ignition etc.
Thanks