How is your dial indicator set up off the lifter? variations in angle and such can affect @ .050. I like to do .050 and .100 before and after max lift /2 to get a good read on Intake max lift (intake centerline)

You are using a solid lifter I take it??

You indicating right off the lifter? indicator in pushrod in lifter (I have a short push rod made up for this! Or off the valve retainer?