See, I don't get this part. The only way to avoid this is to leave the engine absolutely bone stock.
Even the Mopar Performance cams, once you get to a certain level of performance, require machine work to the heads to get the factory spring pockets to work with the springs needed for the upgraded cam.
If you put in a bigger cam, from ANY manufacturer, you have to make sure that the springs are at the proper installed height and have the right PSI. And that requires machine work even on the stock heads. This is simply a part of installing a bigger cam.