As noted in the subject of this Topic, we also need to address the difference(s) between the C7ZZ's and the C8ZZ's. The first attached picture is of an NOS C7ZZ-13489-A Service Part and the second picture is of an NOS C8ZZ-13489-A Service Part. By the pictures, I don't see the difference. What am I not seeing ? Both have the gasket and the studs.
Another item of interest is that while the 1960-68 MPC shows the change from the C7ZZ-A to the C7ZZ-B as being 4/17/67, the July 1967 OSI Catalog does not show ant change from the "-A" to the "-B". This change is, however, shown in the July 1968 OSI Catalog. Further, the July 1969 OSI Catalog shows the C7ZZ -B as being R/B (Replaced By) the C8ZZ-A.
Bob