Will the '68 Dart 225 run again?

Wow, never heard of that rule. I've got my '68 registered as Historic in MD, and use it as my daily driver.

As far as registering it one way or the other, I don't know what PA's rules are, but here in MD, it exempts me from inspections, emissions, and gives me a pretty good cut on insurance.

EDIT; another consideration to take into account is the police activity in your area. I don't necessarily suggest this, but if you don't have much pressure from the tough-by-the-books cops, you could probably ditch the Intrepid anyways and use the Dart. Again, back to my Dart, it's been my experience in the past few years of dd'ing old cars that unless you're driving like a maniac, they'll leave you alone.