Just an idea here.. what about using a 454 block & 396 crank w/ a solid lifter cam about like CP said... all roller... keep the heads- port & polish... 10:5 to 11:1 pistons, single plane int, 850-950 cfm... etc... get some extra R's & twist it like a small block? Run good electronics & flow through some 1 & 7/8" or 2" quality headers... 450-500Hp & revs like a mouse.
BTW: Welcome to the forum!!! Scooter