700 Hp on NA pump gas

RAMM said
I can put you in touch with the owner of this one. Owner wants to build something different now, I'm sure its for sale. J.Rob
This 436ci Small-Block Mopar Makes Big-Block Power On Pump Gas

Crazy torque per cid.
If the OP goes with heads that flow closer to 400 cfm he should be able to reach his goal.
But buying that engine would be more cost effective.