Upgrade to Disc, or do Alterktion???

Someone mentioned that the Mustang II front end is wider. Didn't sound right to me. I just checked specs and the front track on that car was/is 57.5 in. the front track on the Duster is 59.1.

OP, I strongly suggest you read Mopar Actions series of articles on brake and steering upgrades. Go to Mopar Actions web site and check for back articles you can order. Some of them are on line as well. This is GOOD information.

The stock front and rear suspension is a good one and so is the steering - provided, of course, that it's in good shape! And there are a number of persons that actually do "race" their cars with a "basically" - if not fully - stock suspension, right here on this forum; in addition to Rick E (Green Brick, as mentioned). It was either the first or second year that American "Pony" cars ran in Trans Am racing, a Dart, Valiant or Barracuda (I can't remember which) won.

If you look at that altercation rear end, the coil springs are INSIDE the rear frame rails. Leafs are on the outside, which is much better! If you doubt this, picture leaf springs just on either side of the differential and imagine how little control your rear suspension would have!

I won't dis anyone who's bought and put on these "kits"; and if they say they work, fine; if they like them, fine. Many of us have or had any number of more modern cars with R&P, struts and IRS - and/or have driven any number of others. I have, including the present gen Mustang GT, and I own a Dodge Magnum R/T. So many of us do know what "modern" American cars handle like. The old A body suspension, when properly set up, just ain't that bad.

I would love to actually see lap times of a good example of each type suspension on very similar cars, or hear from anyone who knows of such a comparison.

And one last thing - once you go with these kits - it'll be practically impossible to turn back.