[earossi]

I'm not certain that I would jump to the conclusion that your noise is a bottom end issue. You need to begin by first looking at everything that you touched while doing the upper end.

Start by telling us what your definition is of an "upper end refresh". Was that just a valve job? Or, did you also replace piston rings?

If the engine truly is only 115k miles "old", you should be at about "half life" on the bottom end of the motor. So, I would first look at the work actually performed to find if there isn't a culprit there.

You mentioned that you are now seeing metal shavings in the oil. To me, that is an indication that you are looking at a teardown regardless wherein you will retrace the steps that you took while doing your upper end.

The key to a decision to split the case is examining the rod bearings. If the crank has been damaged due to the failure of a rod bearing, then I believe you should strongly consider splitting the case. In all reality, with the upper end of the motor stripped down to the point needed for head work, you are only about 10-15 hours of labor away from splitting the case and reassembling it.

Just my 2 cents.