I'm digging up this old valve cover thread because I have some pictures to add. This 2011 thread discussed the differences between the Z28/Corvette/LT1/L82 covers over the years. http://nastyz28.com/threads/1970-and-1974-z28-valve-covers.218974/ The old thread indicates that the 1969 covers should be casting number 3932418. These covers had no drippers for the rocker arms. They were used on 1969 Z28 and Corvette L46 engines. I have no pictures of them. They have 3" cutouts of the rim for clearance to the intake. The 1970 covers have casting numbers 3965543LH and 3965544RH. They are exactly the same as the 1969 covers except for the numbers and the drippers were added for 1970. They also have the 3" cutouts. These covers were used on Z28 Camaro and Corvette with LT1 and L46. The 1971-72 covers are the same as the 1970 covers except for another number change and the hole for a push in oil cap in place of the earlier twise in cap. I don't have a set of them to take pictures, but maybe someone with a set can contribute some pictures. These covers as far as I can find information would have casting numbers 3989005 & 3965542. Additional pictures would either confirm or prove me wrong. These covers would be the same as the 1970 covers except for numbers and push in cap hole. Again, the clearance cutouts are 3" on each side. Used on Z28 and Corvette LT1. 1973-77 covers again were different. They carry the casting numbers of HL 3455693 & HR 4455693. This version went back to the twist in oil cap. The drippers are shorter than the earlier covers. The cutouts changed. My set has a 3.5" and a 5" cutout. I have read of others with slight variations on those sizes. These covers were made in both polished aluminum and black for the L82 Corvettes. These are also likely the versions sold over the parts counters at GM for many years.