If you are going for anything other than dyno numbers (ie any reliability) you will want too look at:
Forged internals, maybe sleeves
35R with all the trimmings
damn good tune ($1000)
you may hit 500 without a built motor, but it will not last. If you're lucky, you'll break ringlands and be able to reuse motor parts. If not lucky, you'll break a piston and ruin the block, crank, rods, andmost expensvely - the heads.