1985 Mercury Outboard V-300 V-3.4L Shop Service Manual, Page 120Get this manual
POWERHEAD REASSEMBLY Install crankshaft as foll ows:
ILubricate crankshaft sealing rings with light oil2Check cylind er block to be sure that dowel pins are in place
3Position all crankshaft seal ring gaps (a) straight up4Align hole (b) in upper bea ring carrier and centermain bearing races wi th dowel pins (c)5Gen tl push rankshaft down into position making sure that the dowel pins are lined up wilh the holes in centermain bearings and upper bearing carrier sud cra nkshaft seal rings are straight up