It's like day & night. My father purchased the car new in '70 and ordered it with the basic 4 wheel manual drum brakes. The car really didn't have much stopping power and the suspension needed an overhaul so I decided to go all out and purchase the kit from PST which included everything in the front end, all control arm bushings (front & rear), shocks, springs and rear brakes. The car rides like new. Best money I've invested in the car to date. Here are the links to the site/kits:
http://www.p-s-t.com/gm/gmfdbkconv.html
http://www.p-s-t.com/gm/gmkyb.html
http://www.p-s-t.com/gm/gmfekstd.html#PONTIAC
http://www.p-s-t.com/gm/gmsprings.html#PONTIAC