Ok, the second question is pretty much covered, for your first question, no, there's no chart or anything to tell you what boost level you should be at. These are positive displacement blowers, so for every revolution, they move a specific amount of air, in this case 90 cubic inches (hence M90). Your boost levels will depend on how efficiently your engine can use that air. Things like headers, high ratio rockers, etc help your engine breath better, so they would actually reduce your boost (and increase performance).
