I had a mechanic install a set of AFR aluminum torque monster heads on my BBC. I questioned him as to how long after running them should I wait to have him re-torque the heads. His answer sort of shocked me. So I will run this past the BBC experts here. He claimed that since they were aluminum and not cast iron they DID NOT need to be retorqued. He stated when he put aluminum heads on his 502 BBC he did not re-torque them. I just want make sure he is giving me the RIGHT answer. What is the true answer to this? By the way, he is not a shade tree backyard mechanic and has been a mechanic for 25 years. Thanks in advance.