What's the story with changing the heads every year? You would think if you had a good product with good performance in the range they wanted they would continue production? Just using the base 350 as an example they changed heads every year from 68-76. I understand the later years with smog considerations but 68-70? It's like they made a bunch of #17s and said oh well... for one year we're good and then the fun is up. Unfortunately the next head (#47) although essentially identical, had bigger chambers and less compression. And the next one (#11) continued the trend, same valve size but even bigger chambers for once again lower compression.