64 dart brake/suspension upgrade
I am not sure what 'peace of mind' the Wilwood conversion would bring over the stock brakes....?? They both work fine. I would prefer the stock conversion for cost and for not worrying about F-R brake balance....with the proportioning valves that are right. However, the Wilwood set may weight less, and that is a postive for good handling over less-than-billiardbroad smooth roads.
Poly bushings can be hard on the chassis parts if you don't drive all the time on pretty smooth pavement; they are a lot harder than rubber. They DO stiffen things up quite a bit. Personally, I find re-new stock rubber does a very good job; I would try to buy NOS parts; some of the new stuff is fine but some is made from the wrong hardness of rubber and some parts are too soft out of the box.
Look at Addco for anti-sway bars; they sell both front and reat anti-sway bars; I would be putting on both to keep roll stiffness balanced front to rear. Once you put them on, find a large parking lot and drive arond hard in circles to get a feel for if the car is pushing or the rear wants to slide out so you can adjust some.
And for imporved handling, you realy need to look at a good set of gas shocks.