Seems a lot of expense for minimal gain. Re-Work stringers, re-rig the whole thing, redo the transom, ect... Parking it will also be fun!!!
Also I doubt the stringer layout will easily adapt to stagger. Notwithstanding with the bulkhead space available it would only be a short stagger.
Those boats also react very adversly to moving the CG forward. Just the difference between a cover girl cabin and an extended CG cabin is 2-3 mph, all other things being equal.
From what Otis experienced also proping his boat, when the stern was higher (produced with a 5 blade prop instead of 4) the boat plowed and would not get up to speed.
For the money your talking you could easily modify your mills to 725-750 HP and get in the low to mid 80's...which in my humble opinion is the max you can put thru an XR kind of setup and have a certain amount of drive life left if your gentle to it.
Just my take on it, hope it helps.