CV vs. CZ fan clutches and their applications

[neresto]

There have been questions that come up over and over, year after year about the differances and applications of the 1969-1970 CV and CZ coded fan clutches. I'm starting this thread to help us all better our knowledge and future correct use of them on our cars. Any statements that I have seen on this forum about the CV clutch lead back to the CRG and being a Z/28 only clutch, this is only possibly correct for Camaros. In my experience and research the CV clutch is used on every 1969 and 1970 L-78 L-72 and LS-6 Chevelle with the possible exception of the LS-6 that uses the 064 larger fan blade(feel free to chime in on this one if you have solid evidence on it like a code other than CV on the buildsheet). I come from a Chevelle background and have had all of the above cars in unrestored condition with their original parts and buildsheets. I'm hoping that we can all post to this thread with solid evidence of the uses of the CV and CZ and time frames on Camaro and Chevelle i.e. build sheets, line sheet, broadcast sheets and original examples on cars. This could also help expose any anomalies in plant use and time frames. I'm starting off by posting a example of the Eaton CV, my CZ that I have has a weak stamping so if someone would post a quality CZ example that would be great.