I think this guy figured out the tapping/ticking
#12
#13
I won't have any affect on piston skirts or liners slamming around, but if it's lubrication related it has a chance.
#14
I have run 10W30, 10W40, 15W40 and 20W50 and the tick is always there, more pronounced with 20W50 than with 15W40. 20W50 actually made it much worse than before. I also ran for 500 miles with 1Qt MMO in 15W40 and the tick went away, go figure.
#17
A good auto machine shop should be able to handle pinning the liners for you, but it sounds like it probably won't be cheap...