The small block Chevy engine has six freeze plugs, two on either side of the engine and two in the rear of the block. The freeze plugs are made of steel and are subjected to corrosion if the proper antifreeze mixture is not maintained. Not only that, but regular green antifreeze turns acidic if not changed every few years.
Raise and support the front of the vehicle on jack stands. Use a drift and a hammer, placing the tip of the drift all the way to one side of the plug and tapping it with a hammer. The idea is to rotate the freeze plug like a revolving door. Push in on one side and the opposite will come out where it can be grabbed with pliers.
Tap the drift until the freeze plug rotates enough to grab it with pliers and pull it out. If the freeze plug is so corroded it begins to break up when struck, use a small nose drift to punch a hole in the center of the freeze plug large enough to get the screwdriver into it. Use a block of wood for leverage to pry the freeze plug out with the screwdriver.
Place the new freeze plug in place and lightly tap its outer edge with the hammer, alternating tap points around the circumference until it is seated perfectly straight.
Insert the correct sized seal installer head in the freeze plug and push the extension into the head. Tap the freeze plug in until its outer edge is 1/16-inch below the block surface.
