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.

[neresto]

1969 COPO buildsheet

[neresto]

1969 Framingham L-78 sheet, note the use of the DV fan pulley and not the 824BV. This is the type of anomalies that im talking about.

[neresto]

1970 Kansas L-78 Chevelle

[neresto]

1970 LS-6 Atlanta 02D built 4:10 auto 772 fan and CV clutch

[Ls6 Ragtop]

Mike your LS6 buildsheet answers your 3976064 and CV clutch application question. The W in box 21 is the code for the 064 fan and of course it lists the CV clutch. This is the only clutch used on shp big blocks in 1970. L78's use 772 fans and use code V as it's identification code. I do not have any evidence supporting the use of a 772 fan on an LS6. All my documentation lists either the W code or just 64 depending on plant code usage for an LS6 car regardless of whether it has 3.31 or 4.10 axle.
My research on other applications agrees with your findings, 69 Z28 Camaro, 69 L78 and L72 Chevelle as well as the above listed 70 applications. Not used on 69 shp big block Camaro or Nova.
Chris

[SeattleCarGuy]

Great info, thank you.

Do you know where I can find the correct fan clutch for my '69 L78 Nova? Thanks

[bkhpah]

There are no clutch fans for 69 L78 Novas...BKH

[bergy]

Mike - 1969 COPO with an open element air cleaner?

[Ls6 Ragtop]

Bergy, Those buildsheets are all for Chevelles.
Chris