I used med glass beads on the outer cases, barrels and head. I kept the pressure low, about 80-100 psi. At the lower pressure it tends to burnish/peen the surface. Keep the beads clean. Start with a very clean case. Use some Dawn dish soap in hot water and scrub the cases before you start If you do bead blast make sure you do not do the inside cases or any part which is internal to the engine. I used aluminium tape and covered the mating surfaces. This will hold up to the blasting. I also covered any small holes with alum tape. To keep the beads from going into any drilled passages I used plummers putty and inserted it into the opening and then taped over this. You need to think about all the openings. You do not want to get anything in the oil or any other passages. Remember the two little holes that are drilled into the oil passage on the (I think) lower case. Can't remember for sure. After your done remove all tape and putty. Do the Dawn thing again. Make sure you rinse the passages several times. I also scrub the cases with either 0000 or 000 steel wool on the outside while using Dawn. The last thing I do is spray brake cleaner into all the passages and let them drain out. Use compressed air and blow to the large openings. The results are great. Sorry for the long answer