The 1929 engine was a 194 cubic inch model, the first 6-cylinder Chevy produced. It was used through about 1933, along with a 181 cubic inch model and a 207 through 1935. The 216 engine was introduced in 1936, and the same basic block design continued through 1953 with several modifications and different displacements. In 1954, a redesigned engine was introduced with a different oiling system and 235 cubic inches. It was used through 1962. The 194-207 engines were slightly longer than the 216-235 series, and most parts do not interchange with the 1936-forward engines. Parts are scarce, but still available at times. I have a set of reconditioned 207 connecting rods stashed away somewhere, waiting for someone to need them.
Jerry
