360 Magnum building on an existing bottom end

The EQ heads come in a version that accept the LA style intake bolt angles.
Not any more, they quit making those a number of years ago. Maybe someone still has a set stashed away that they'd be willing to part with, but that's a longshot. Stock pattern magnum heads can be redrilled to LA pattern, though; if you can find a shop willing to do it. A member on here has a jig he loans out to do the job yourself, but don't know the status of it at the moment. A quick search on the Magnum Swaps forum should tell.