This option still seems a possibility to me. Others have apparently done this on other applications.
http://www.moparaction.com/Tech/quest/internally.html
No weight to get in the way.
I noticed too the mopar performance flywheel is cast so there's no real advantage other than the right balance.
I'm not confident enough to just buy the book and do it (not good if you get it wrong) but I am curious to hear opinions from anyone who's done this kind of thing.