Hey Steve! I have a '72 GT, and I upgraded my front swaybar and added a rear (I don't recall the exact diameter of either). BUT: best (auto) decision I ever made. I love the way my car handles - balanced, flat, and responsive. Steering input is a bit higher than previous, but I'm running the stock steering wheel; and it's pretty big, so no problem. Every time I drive it, I love that car a little more.
Also upgraded the front brakes (drilled/slotted and V8 "green stuff" pads) and ensured the rears are perfect; added driving lights and put all headlights on relays. Now I just need to get the rust taken care of. (And then it's limited slip, traction bars, and supercharger). Then, I'm done. Maybe. :smile-new:
Phil