This whole topic is a good one. I dug into some of my other GM manuals with clearer text. I appears that the revisions were made in the 5/13 and 6/3 of 1968. So those early cars that still have the shield on them would appear correct. We have put starter shields on most of the restorations in the past, but I was never sure what was right. But they do work well, and in most cases we also change the selinoid spring to the heavy duty one available through any GM dealer. It will help start some of those peskey high compression big blocks when they are hot...BKH
