AC Delco part number assistance needed

[Dave S.]

My Delco parts book lists a CV-691-C PCV valve for 65-68 396 and 427 applications. I'm not familiar with 691 PCV valves. Is the 691 NCRS correct.? If so is it for 65-68 Big Block.? Any help is appreciated.

[Joe L.]

Re: AC Delco part number assistance needed

Dave------

The AC CV-691C was the PCV valve used for 66-67 Corvette big block applications, with the possible exception of 67 L-68 and L-71, as well as many 65-68 passenger car big block applications.

In SERVICE this valve was known as GM #6421981. It was discontinued from SERVICE in July, 1969 and replaced by the AC CV-736C, also known as GM #6423695. The 736C MAY have been the valve used for 67 L-68 and L-71, although I'm not sure of that.

[Dave S.]

Thanks Joe *NM*