[Blue Bowtie]

The lifter gallery may be somewhat starved for oil, or a lifter(s) in that bank may have excessive bore clearance. Is the oil pressure normal?

You could loosen a couple rockers (count the turns to be sure, even though the valve train on '91-up BBCs should be non-adjustable) enough to get them out of the way and remove their push rods. Check the push rods to make sure they are clean and clear through. Check the oil holes in the rockers themselves.

The fact that the entire bank is relatively dry, however, tends to indicate a supply problem in that bank. Short of disassembly, you might try an engine flush or changing to fully synthetic lubricant to help clean out and accumulated deposits.