Some of these answers are correct. The 351w is called a Windsor, because it was built at the Windsor plant. The Cleveland was built in the Cleveland plant. A 302/289 are the same block, just diff. cubic inches. They both share similar characteristics of the 351w, such as bore size, water passages, etc. That is why heads, timing covers, water pumps and other things swap over. The 302 was built at a different plant, but they are linked becuase of the fact that they are similar.