Which heads on 1994 magnum block

Nebraska has some crazy changes in elevations with the average being 2600ft, which by itself, from sealevel, is gonna cost you about 14psi of cylinder pressure. If you are at say 3500ft, this will cost you an additional 5psi. So right off the bat, from a performance standpoint, you will never , with a 400+ hp cam, make enough pressure with iron heads, to get any decent low to midrange power, unless you happen to be close to sealevel, and set the pressure to the max. So then, if you are a streeter, and are dead set on 400hp or more, then you are pretty much forced into an alloy head.
If you run alloy heads, you can really bump the cylinder pressure up, which makes for a heck of a peppy engine and can lead to great fuel-economy.
However, on a true 9.600 deck, your speed-Pros look to be ~.027 below deck which at 4.02 bore is 5.6cc.
Adding the 5cc for the Eyebrows, this totals 11.6cc
Adding 8.6 for the .039 FellPros, is 20.2cc
to get to 11/1 would require a total volume of 74.5cc, so then
the heads would have to be, 74.5 less 20.2=54.3cc..
I don't remember ever seeing chambers that small.
But, I do remember seeing as small as 57cc. With these, the total chamber size would come in at around 77.2 and the Scr at 10.6. ... which looks pretty good, until.....
you contemplate those elevation changes again, and the fact that those changes are gonne wreak havoc with your pressures; and so, you can't just stick any old cam into it and expect it to run great, never mind getting 400or more hp out of it. I mean at sealevel you might make the number, at say 5300rpm, but the bottom end will already be soggy, for lack of pressure.
IMO, you are gonna need a supercharger to get there at anything but sealevel.
Now, if you want a strong-running steeter, she don't need to be 400hp. A streeter is a two-gear car, because most times, the top of second gear, with a street-friendly rear gear, is gonna be well into speeding-ticket territory. A couple of those could see you walking, if a cop catches you.
So then
IMHO,
you need to make some serious decisions right now, before you start spending money.
1) what elevation is your car gonna be running at?
2) Are you willing to stay at that elevation, or if not, then are you willing to deal with the consequences?
3) What is the intended usage?
4) What trans-ratios, and what rear gear-ratio, do you intend to run?
5) what grade of gasoline are you willing to pay for?
6) and besides all of that, the biggest tire you can fit under a stock-tubbed 71 Dart is a P255, and a stout 360 at 400+ hp will annihilate those right thru First gear, and most if not all, of Second, in a hurry .... as will 350. Down, in First gear, so will 300hp even 275, maybe even 250 depending on the gearing.