I wouldn't set it once and be done. Do it properly, set the exhaust lash just as the intake valve begins to close. Set the intake lash just as the exhaust valve starts to open. Stud mounts are NOT shimmed.
Ochohill is absolutely correct, you need to measure the length of the push rod. If you're using your stock rods they are the wrong length. I also found on my Trickflows that the intake and exhaust push rods require different lengths. If you cut corners you will have problems down the road.