The first, second and third thing you do before starting measuring and assembling your short block is to clean it, clean it and clean it again. you can not get the block too clean - it just spent a considerable amount of time being machined. Several pounds of aluminum shavings were produced along with quite a bit of very hard steel sleeve machining left overs.
You can see that the oil galley plugs have been remover - there are three of them and they should all be removed to clean the block and then replaced.
For those that want a very clean block we can bead blast the block before starting machine work - if the block has been bead blasted you may have to clean and flush the block several more times to ensure that there no abrasives left.
When you think you are done - clean it one more time, then spray down the cylinders with WD40 and cover with a big trash bag. Never leave the block exposed when not working on it. Dirt and dust are evil and have no place inside an engine.
The next step is to clean the assembly area. I will wash the floors before each engine project starts. I am planning to dedicate a corner of the shop for a clean room for engine assembly only.