Ok, this is my plan as I'm running short on time. I have a 4.0L head in the back yard that needs to be reworked a bit so I'm going to put that into service instead of reworking the 4.2L head. I'll need to get a 4.0L exhaust manifold and new head bolts made specifically for the conversion. This was a future planned conversion but now has been moved forward to be done now. In the meantime, I'll give the BG 44K another day to see if it's any carbon can be cleared up that might be causing problems.

Question:
While I have the head off is there anything I can do to evaluate the condition of the piston/cylinder/rings on any of these cylinders? That is, if I move the piston back and forth to view any slop, is that a viable test? Can I measure to determing how many times, if any, the cylinders have been bored over? Anything else I can do? Thanks for any insights and suggestions.