Changing crankshaft bearings with the engine in the car.

I've done it on a slant six. I have the official service tool (for bearing removal) that inserts into the oil hole, but the cotter pin idea above looks like it would work also. You can also get plastigauge and check for proper clearance with the new bearings. If the clearance is still a little too big, you may be able to find bearings that are for undersize crankshafts. The hardest part (besides getting on/off the floor 100 times) is finding room to use a beam torque wrench in the limited confines under the vehicle.