I'm checking the installed center line (ICL) on my 440 that I'm putting a Summitt 6401 cam in (LC '77 440, Holley SD intake, headers). I'm going to set it up with the dial indicator on the lifter and no valve train, but I got to thinking that with the valve train set up it will effect the #'s, I'm just not sure how much. Has anyone ever compared the two?