Pro Gram as noted, and I don't use them unless it was honestly capable of 550hp and steady high rpms. It's one of those "to each there own" things. If you are planning to make 600hp you are not tossing together a cast crank with a set of RPMs. You're going to be using good or really good heads, good rockers, a solid roller cam, good crank and rods... A budget for an honest NA 600hp will be between $8-10K depending on the top end package. For me, a factory block for that will cost $2400 to get ready. That's magged, sonic tested, fitting billet caps on #1-4 mains, studs, align bore and hone, square deck, bore, plate hone, bush lifter bores, modify oiling system, and de-burr. The caps and studs will run another $6-700. By the time you're done, you;ve got a block that will take 600hp, but it's maxxed out. For another few hundred you could have one that can handle another 2-300hp and be rebuildable even at much larger displacements.
