Magnum heads and cam selection??

I'm thinking about putting together a bracket package using the Indy LA-X heads. I heard you can only go so big with the cam if you use Magnum heads because after so much lift, it will require machining??

This will probably be an LA engines using the Magnum heads and hydraulic cam.

If I want to go with a solid cam, I guess I am stuck using LA style heads due to the valvetrain arrangement-right?