How much HP is it taking now?
How much do you want to have total with the spray?
I have a friend who has raced heads up(not a Mopar engine) with both types of blocks, aluminum and cast grey iron and went faster and with the iron blocks, he used all three types of power adders on that car, NOS, twin turbos and a Pro Charger. The iron wedge head block was the fastest and quickest

I'm at the limits of the stock 440 block now and would like to spray a lot more than the 200 shot that we are using now and at the same time make a little more HP n/a.

At the same time I will be upgrading heads as well to support the larger cubic inches.

What are the pros and cons of aluminum vs. iron on the street other than the obvious weight differential?

Yes the alum moves around a lot more and yes the iron makes more power......BUT when you look at repairability and the fact that you can LOSE 100+ (aluminum) rather than gain 100 (Iron) . And the fact that Indy Cyl Head has a great owner now, I would buy the Indy Maxx. Ive had one for well over ten years now and its still going strong. Makes over 900 NA and takes 400+ nitrous and sill has great pan vacum. MAKE sure whoever hones your block knows how to hone alum blocks, thats the main thing to worry about. Other than that you need to deal with the lash growing and thats it.

what heads do you want to use?

Streetable? now not so much, however when i first put the Indy block it was very streetable. It had 440-1 ported at Modern Cyl Head. A .660/.670 roller cam (Scott Brown) that was pretty mild and didnt use killer springs. I was 4.15 X 4.375 , 499" and the fastest it went was 8.40 @ 160, Back then i was leaving on a plate with a .070 nitrous jet and progressing a .032 direct port on top of that. The car was 3500lbs back then, full interior all glass windows, wipers , radio etc

Like i said, biggest thing is ring seal with a nitrous motor and you need to get someone to hone the block that knows this.

Dont know where you buying the heads, I like the 440-1 but consider getting the chambers softened and yea i know no one wants to spray a lot of nitrous, but it happens LOL , that said the cam will be critical in how timing sensitive you are at higher levels of nitrous. I would have BES do your headwork, and Scott Brown make your cam. Just remember on this combination that you may eventually end up single digit timing, especially if you dont get the chambers softened. My current cam opens the exh way early, obviously hurts NA power but helps a lot when using a lot of nitrous.

Consider getting your plate? flowed, Not sure what your using right now, but for years i resisted doing this, but finally did it and it was a great help. PKRE, or Induction solutions, Induction solutions sells some nice plates, the Holey Moley is pretty similar to a NX single entry crossbar (thats what im using) Get a plate that goes to 600+ because you can always dial it back to 2-300? THat and get a decent progressive, Edelbrock is good entry level, but there are a lot of choices out there.

Pay attention to SLR, dont know what rear gear you have but beleive me , you dont want to use a 727 with a 2.45? first gear and 3.90 rear, It will make it hard to hook, and it will want to knock the tires or stand up if it hooks, YOu want a SLR somewhere 7.50 or less, the more power the less SLR. RIght now i am at 6.068 thats 1.48X4.10. SOmething to remeber and experiment with. Make sure your trans can leave in 2nd and then myou can have 1.45? and 4.30 or 4.56. Unfortunately its a trial and error thing, and you be surprised the more you get to 1,000 and over , the less SLR you need

ANy other questions let me know

I am using the NX crossbar single entry plate. With a trashcan and an NX .310 fuel solenoid. It was flowed by PKRE . THe Holey Moley is very similar to the NX plate. Im using a Holley Dominator ECU for the ignition and to control my nitrous. WHen your looking at progressives see if you can get one that controls the nitrous and fuel independently. That helps a lot when getting to larger tunes to keep it from going lean early into the run.
Definitley think things through, dont get whats "good for now" as honestly the better stuff will work and give you room to grow later on.
Good luck sounds like a great plan , and soon youll be needing MORE rollcage..LOL

Chuck at Best is also a great resource for sure, as well as an INDY dealer

I use to like that tan dart when it had a column shifter

It was different tho.

I have a ?.....what is softening the combustion chambers ?

I use to like that tan dart when it had a column shifter