Be sure to match what you have with a new one before buying, as there are some with flange style, flangeless style (chrome ring), then there are end oiling style, and newer evo style. Look at the motor where the nose cone bolts on, look to the left of where the breather gear is, about 10:00 oclock, some have 3 small holes and older ones with 4 small holes for oil carry over return,(uses a different gasket also) my 2002 BD motor has the older style 4 holes.
Is your old one beyond repair, could it be drilled out more a put in a threaded insert,
heilcoil?