Before installation of the crankshaft, the main bearing oil clearance must be checked. Position the left crankcase section on a workbench with the bearing saddles facing up and wipe the main bearing surfaces with a clean lint-free cloth to keep them spotlessly clean. Clean the back sides of the main bearing inserts and lay one bearing half in each main bearing saddle in the crankcase, ensuring the tab on the bearing insert fits into the recess in the crankcase without hammering or damaging the bearing faces, and without using lubrication at this time. Clean the faces of the bearings in the crankcase and the crankshaft main bearing journals, then carefully lay the crankshaft in position in the left crankcase section. Trim three pieces of Plastigage slightly shorter than the width of the main bearings and place one piece on each crankshaft main bearing journal, parallel with the journal axis. Clean the faces of the bearings in the right crankcase and carefully lay it in position without disturbing the Plastigage. Install and tighten the crankcase bolts without rotating the crankshaft. Remove the bolts and carefully lift off the right crankcase section, ensuring the Plastigage remains undisturbed. Compare the width of the crushed Plastigage on each journal to the scale printed on the Plastigage container to obtain the main bearing oil clearances, which should typically fall between 0.0015 to 0.0023 inch (0.038 to 0.058 mm). If the clearance is not correct, double-check the size of the bearing inserts and recheck the crankshaft main bearing journal diameters, ensuring no dirt or oil was present between the bearing inserts and the main bearing caps or the block during measurement. Remove all traces of the Plastigage from the bearing faces or journals using a wood or plastic tool to prevent damage. Carefully lift the crankshaft out of the crankcase, clean the bearing faces, and apply a thin layer of engine assembly lube to each of the bearing faces in both crankcase halves, ensuring to coat the thrust bearing faces as well. Carefully lay the crankshaft in the left crankcase section, directing the connecting rods into the cylinder bores, and install the crankshaft/connecting rod assembly onto the bearings in the left crankcase before rejoining the two crankcase halves.