[Ol' Ron]

The method of getting the the right tappet clearance in a flathead is by grinding the dtem of the valve. na has nothing to do with the valve spring. The slight amount you'd remove would not change the valve spring pressure a measurable amt. However old springs loos some of their umph and need some help so measuring this is quit easy take a valve and install it witout the spring and measure the distance between the buid and spring retaier, Now get the bathroom scale out and put a valve in the chiuk of your drill press anf force the spring down to the same numbet and read the dial. It should be 45/50lbs. Not exactily rocket science, just flathead science. The adjustable lifter just makes it easire to get the right tappet clearance. Don't forget to drill the hole??
Gramps