My current block is fine, but I would like to buy an extra block & crank to build. The thing is I don't know what to look out for. Cyl walls will be pulled and sleeved anyway, but I need to know what to look out for when it comes to the crank. Obviously, spun rod and crank bearings is a no no. I would like to know by way of scoring what may have happened to the crank. For example, a scuffed #4 could have been caused by a spun bearing.

 

A spun rod bearing should not be a show stopper, however a spun crank bearing should be. This will depend on what your build plans are. It you plan on replacing the rod, and I think you do, then you control what side the bearing will need to be.