596 casting or 308 casting for mild 360 4bbl

Swapping to a Magnum head is OK as well. But it does incure a few extra costs that you may not be aware of.
Different intake is a starter and a possible balance issue that is easily solved with a B&M flex plate but it is a cost. The rockers are a 1.6 ratio over the stock 1.5 ratio which is nice but you have to constantly do a little math before you get a cam. And then there is new pushrods which is an added cost.
All of which are not a big deal but there.
Just food for thought.