I had a D-Dart back when they were released. Did pretty good with it too. Showed a lot of 327's the door. FWIW, the 275 HP rating was a lie. The true numbers using the e.t formula, it had to be 300+.
That aside, if you duplicate the cam profile, I don't recommend if you're using an automatic.
Also, today's heads are superior when using heads that have been cad-cammed.