I'd be cleaning them super-thoroughly. My choice is wax-and-grease remover and various brushes, plus the compressed air nozzle. Break all the sharp edges on your block first.
All block plugs should be removed, and when finished you should not be able to pick up a smear of colour anywhere internal, using white paper towel. Apply a light coat of motor oil to the bores by (clean) hand as a last measure, and wrap the block completely in a new polythene bag.
Clean the crank and cam similarly, paying attention to the risk of grinding particles being hidden away in them. Again, oil and bag when done. Allow up to six hours for the process, and possibly half a gallon of solvent...