If you torque main bearing cap bolts to 80 pounds you better have an eight point socket to do it. Square 9/16" sockets are impossible to find and using a larger 12 point will round the corners of the square 9/16" cap bolt. Found 9/16" 3/8" drive sockets on Amazon for around 6.00 plus shipping. Then checked at NAPA a little over 4.00 and no shipping. With a 1/2" to 3/8" adapter it works fine with my torque wrench
I have found many of them at swap meets in the "Misc. Sockets" box for 50 cents to a dollar.
Sears has 8 point sockets that work fine on the main bearing cap bolts.