My OEM GM lifters soaked in fresh oil for about a month. I also used an old push rod and pressed the plungers in them to push out the air until they were solid. I like my overkill for assembly and first start. It's only overkill until it isn't.
CHECK PUSHROD LENGTH! THIS WILL TAKE A BIT OF LEARNING BUT WORTH IT. WHEN CAM, SPRINGS, LIFTER TYPE ETC CHANGE IN THIS CONFIGURATION THE STOCK AFM PUSHRODS MAY BE TOO LONG AND CAUSE ISSUES OBVIOUSLY. EVEN IF THE 7.400 SHOULD NOW BE 7.375 OR WHATEVER YOUR IDEAL NUMBER IS AFTER USING ADJ PUSHROD LENGTH DETERMINATION PUSHROD' YOU JUST MAY BE SURPRISED!Unfortunately the VLOM got thrown out a week or so ago.