Just out of curiosity, what cams are you looking at? Most 360 mag roller cams I have found for the magnums are either racing cams or factory stocker replacements, nothing in the mild-med performance range - as far as I have found...
I haven't started the hunt yet. The cams in the crate motors seem pretty decent, at first look.
Honestly, my first call was going to be to COMP Cams... I like them a lot.
If I can't get the performance I want out of the actual cam, higher-ratio rockers are an option.