Oil consumption and ticking after cam swap?

Magnum engines use positive seals, not umbrella seals, but you can definitely cut or grind the guides down using a number of different methods with varying results. Just another modification, and end result will be as good as the effort put in.
On Magnums, you need a cutter because of the two different diameters that need to remain intact. One is the small diameter that the positive seal goes on, and the one below it is larger and used to position the bottom of the spring.