Hard Block

HP levels are always subjective. Running AL rods will help a ton. As do light pistons and a good crank. The less the parts move and flex, the more power the block can take. But there's also the economy of prepping a stock block. If you dont have to run one, and if this is a project that might have some growth later (bigger, faster, whatever) then in many cases a new block is only about $1500 more than a factory block with all the treatments. When you are spending way over $10K for a budget race engine with decent heads... Whats another $1500 for expandability and room to be freshened?