Big Block power with better heads???

Great idea, but, i honestly don't think that it would sell much and be cost effective.
What comes to mind is that people would just put a BBC in their Mopar, mount it, and build exhaust if they wanted this sort of configuration.
I think you should spend time on a different head design for the BBM rather than a block design that uses the BBC heads, and that will keep the purists on board with you.
You are looking at a very niche market here, think of Sonny's engines, but a lot cheaper.........
I think it would be trick, but the R&D costs would bankrupt you unless you had a lot of backing.
I'm not particularly brand loyal, and do recognize the benefits from your idea, but selling it to the public would be tough IMHO.
I for one would go with 2nd gen Hemi if i wanted that kind of power, and you have the looks to boot. That's tough to beat.