Building a 331 or evan a 347. I read where most guys say that a 302 based block can't hold big horsepower. But then I hear some guys using a stock block and having cars with 600 plus horses? I don't want to build a 351. I would rather stick with the 331 but I am worried that the motor won't hold up. I want to be in the 550/ 600 horse range. Anybody with input on this?