900 wedge HP without power adders is almost impossible/ at least very hard without 4.5 inch bores
and it is silly to think that a stock block will hold 900 HP for long no matter what the heck you do to it ( unless perfectly tuned turbo or the like)
Please call Marsh Perf 336 283 0800 and get a new 440 block from him--he has two in stock ready to go --not cheap but hey he has the only two on the market I am guessing
DRY SUMP DRY SUMP
A Hemi is the right direction for that job but bet the bar is already set pretty darn high in that class
Just no good answer on making that goal with a $50 block and spending a grand+++ to slightly improve it is still a crapshoot
Wet sump in that application is rolling the dice