First time swapping edelbrock aluminum for 915 cast iron heads.

And you are saying the cam would be to big (484 lift) with his combo. Right A/J?

NO...I'm saying there is so much more potential in the combo
that at higher pressures that you could easily give up some duration.........if you wanted some some more bottom-end and midrange. OP didn't state how he intends to use this vehicle so I can't speak to the cam choice
The 284/484/114 cam is about 241*@.050 ..This is pretty big for a SBM streeter, maybe not for a BB,but at 10.2 with alloys it's gonna be a little soft on the bottom.
The clutch will help get the engine thru that, but it won't be a dump-it-and-go deal.
The lift is,even with 1.6 arms (and .516 lift),barely tapping into the alloy's potential.
That cam may not wake up until around 40mph with 3.55s. It's a good thing the 67 Dart is one of the lightest of the later generation A's, and the 383 is a typically pretty good on power.
So the bottom line to me is;installing just alloys is a lot of money for very little gain.I like to get the most bang for my bucks.
But OP says he was happy with the iron combo, and since the parts are already chosen, we'll have to see how it plays out.
And that is my opinion.