+850hp for sure.

Typically the exhaust valve has to be rotated a couple of degrees for clearance to clear that size intake valve, who offers MP heads with that size valve? I thought Stage V and Indy were the only ones. You also have 1 more point of compression than mine, but your cam and intake are milder. That engine will be a beast if those heads flow what the others do with that size valve! As far as pump gas goes, until you get it sorted out, I would limit timing to 34* and run 50/50 mix. It will be very close, but it might make it. Is it in an aluminum block, I am assuming no because you said mega block? Wish mine had 2.30" intake valves...