I like them. I had a Magnum 270 in a 350, and I presently have a Magnum 280 in my 383. You can run a little more compression with the Magnum cam than you can with the XE cams, and you don't get the clicking noise of the valves snapping shut that you get with the XE cams. Personally, I think they are easier on the valve train. On the Desktop Dyno, my engine with the XE274 made a little more hp from 3000 through 5000 rpm but the Magnum 280 cam surpassed it at 5500 rpm. You can't go wrong with the Magnum line of cams in my opinion.