Though most of his customers build 360s, Brian said there are a couple of advantages to building a 318. First, people are giving them away. He paid $50 for the 318 on the left-and that was for a complete short-block. The 360 on the right can cost a couple hundred dollars more just for a bare block. A second advantage to building a 318 is the main bearing journals are smaller than the 360's. All LA blocks have a 2.69-inch main bearing journal diameter, with the exception of the 360, which has 3-inch mains. The smaller diameter of the 318 or 340 block means lower bearing speeds, less heat, and longer bearing life.