Installing Valve springs

Were you planning to make sure they are installed at the correct height, or simply stick them on wherever they land? You can replace springs easy. If it's a mild spring, not a big deal. But if you are looking to match a cam's power band, and it requires a double spring or strong single, you really need to get the installed height right or you may have issues. Double springs also require machining or guides and spring seats...that you cannot do "on the car".