To make that much power, the RPM heads need so much work that there is no sence in going that route. You have basically two choices; build an engine with the parts you have and it will make x-horsepower, or shoot for the 650-700 hp range and make the parts choices accordingly. Here is what I would propbly do to keep the budget reasonable. If willing to retain the stock crank I would pick Mahle pistons and rigns for it and bore the block for them. Rods, from 440 source or equivalent. Enlargen the oil galleys of the block and use a 1/2" pickup, main studs and linehone the block. I might also do a short fill for the block, which should be done before machining. Last thing would be trial assembly, measurement and cut the decks to achieve zero deck height. For heads I would choose Pro Comp aluminum heads and port them. I might use other rockers depending of the budget, Harlan sharp or even the Indy rockers may be better than what pro comp offers. Indy rockers have greater offset and the heads require some grinding to fit them. For the intake I would use Edelbrock Victor with a 2" dominator adapter and a 1050 dominator carb. You should end up with around 11:1 CR which should work fine with 98E gas you have, no problem there. I would use an old tried and true cam motion roller available from Indy, 276/283 at .050" and .69"/.63" lift. Then get the lifters etc where you can get a good deal and last order the pushrods after you know the lengths required. 2" headers, a good ignition and I'm pretty sure you should be in the range you desired, or if eveything goes like in the movies, perhaps even a little beyond.