Broad question from a rookie

Thanks for the information, I have heard the 904 is plenty strong with heavy duty upgrades, but hadn't seen it rated to handle more than 400hp. I have tons to learn regarding the heads and the cam but I'm slowly learning. When you mentioned a roller block are you talking about a later model Magnum 360 block? I'm so new it's pathetic lol! I've read that the LA 360's have a flat tappet cam? So I'm just guessing about needing a Magnum block... thanks for your time and your help