What would you do?

Actually, your results to me mena you have other issues. Possibly valve sealing, or rings not seated. A bad lifter will open a valve later, and close it earlier, leading to a higher test result for a given cylinder. (the intake closing earlier gives the piston more "time" in crank degrees to develop cylinder pressure) I'd be looing more at the heads now than anything else. Pull a valve cover, pull the rocker shaft off, and run a straight edge along the tips of the stems. If they are all set to different heights, take the heads to a good shop and have them fixed. It's an easy way to see how good a shop is at doing valve work.
My $.02 anyway..