Crankshaft installation is the first step in engine reassembly. It's assumed at this point that the engine block and crankshaft have been cleaned, inspected and repaired or reconditioned. Position the engine with the bottom facing up. Remove the main bearing cap bolts and lift out the caps. Lay them out in the proper order to ensure correct installation. If they're still in place, remove the original bearing inserts from the block and the main bearing caps. Wipe the bearing surfaces of the block and caps with a clean, lint-free cloth. They must be kept spotlessly clean. Clean the back sides of the new main bearing inserts and lay one in each main bearing saddle in the block. Lay the other bearing from each set in the corresponding main bearing cap. Make sure the tab on the bearing insert fits into the recess in the block or cap. Caution: The oil holes in the block must line up with the oil holes in the bearing insert. Do not hammer the bearing into place and don't nick or gouge the bearing faces. No lubrication should be used at this time. The flanged thrust bearing must be installed in the proper cap and saddle. On four-cylinder engines it is number two (counting from the front of the engine); on all six-cylinder engines it's number three. Clean the faces of the bearings in the block and the crankshaft main bearing journals with a clean, lint-free cloth. Check or clean the oil holes in the crankshaft, as any dirt here can go only one way - straight through the new bearings. Once you're certain the crankshaft is clean, carefully lay it in position in the main bearings. Before the crankshaft can be permanently installed, the main bearing oil clearance must be checked. Cut several pieces of the appropriate size Plastigage (they must be 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 caps and install the caps in their respective positions (don't mix them up) with the arrows pointing toward the front of the engine. Don't disturb the Plastigage. Starting with the center main and working out toward the ends, tighten the main bearing cap bolts, in three steps, to the specified torque. Don't rotate the crankshaft at any time during this operation. Remove the bolts and carefully lift off the main bearing caps. Keep them in order.