How old are the lifters? If they're new, or recently-installed, let me suggest a little patience. The more often they're run up to operating temperature, the shorter the time will be that they're likely to rattle before quieting down. Tinkering with the noisy ones is simply going to prolong the break-in time before they start behaving, if they're ever going to do it. There's a tech tip somewhere that describes a couple of modifications, one to the bottom of the pushrod, and another to the lifter itself, to help purge trapped air. Since stovebolt pushrods ae solid, and oil doesn't flow from the lifter to the cylinder head area through the pushrod, it's necessary to create a path for trapped air inside the lifter to be purged quickly.
Jerry
