I've been running solid cams longer than most of you been alive. As stated above , if your going for the ultimate tune to get that last .ooo1 out of your engine you won't get get it with manufactures spec.'s, but there close to what you need. The factory didn't run your combination. If your a street / strip guy set it at manufactures recommended tolerance and be done with it. And a side note, you don't have to recheck them every week either, if you find that you have loose lash there's only two things that could be wrong, you didn't set the lash right or some thing is wearing.