My opinion is that 2 sleeves are fine as long as they are not next to each other, as that weakens the deck and will leak water eventually. One on each bank is no problem, or like mentioned above, one each end of the same bank, etc. Each sleeve will cost approx 100 or so, for the sleeve and the machining/install (around here anyway, could be more or less at your machine shop. If the block sonic tested good, use a .093 wall sleeve instead of .062, close to standard bore, then bore .030 over, then final hone with plates to .035 or whatever final bore will be for all cylinders.