Freeze plugs are easily installed with a large hammer and the proper-size socket. In this case a 1-inch socket is used. Most freeze plug kits are available in brass or steel. Brass may cost more, but they dont rust so they live longer. Remember to add sealant around the contact area. If youre building a 400ci small-block, remember that many used two more freeze plugs (one extra per side) than other small-blocks.