I thought I hurt my new 347 so I pulled the motor without even looking under the valve covers.Well as we took it apart we found that I just broke a rocker stud . While I was having the block checked out I was offered a $ 1000 and a 351 stock block for my AFR 185 heads. Long story short, I want a streetable 408 with at least 450 horse to the wheels. I'm looking at the AFR 205's and the 225's but AFR says the 205's are good for 331- 392 cubes and what worries me about the 225's is that they are good from 4000 to 8000 rpm. NOT TO STREET FREINDLY. any suggestions ?