Depends, if you're talking about an aftermarket version of the magnum head ie. Edelbrock or the new iron Indy versions it should be fine especially if you get the LA shaft mount rockers. If you're thinking about factory heads, I am not all that impressed. True they have somewhat better ports and flow as cast, but they have 5/16 in. studs, non adjustable rockers and are prone to cracking, especially between the center exhaust valves. No one has ever shown a ball stud rocker to be superior to a shaft mounted one. There's a reason why Chevy guys buy expensive stud girdles, and even more expensive mini shaft mounts for their heads.