Which caltracs for '71 duster?

Go straight to the source and ask http://www.calvertracing.com/
There are a few guys out here running them, but I haven't tried them yet. I don't know how dangerous it is to run SS springs with Caltracs, but you're wasting money to get SS springs if you plan on running Caltracs. One of the main pluses for SS springs is increased stiffness in the front segment. I know there are other advantages, but when you use Caltracs what you're doing is basically making the front segment almost solid. Anyway like I said I haven't had a chance to play with a set yet, so I could be totally wrong. But in my opinion it would be a waste of money to buy both. If I had a choice between the two, I would go with the Caltracs.