69 Tripower PCV Valve

[Chuck G.]

The 68-69 Judging Manual states that Holley equipped vehicles use a #CV746C PCV valve, and that Rochester equipped vehicles use a #CV736C. I have one of each. In 2 of the restoration catalogs, namely Paragon and Corvette Central, they sell the paper "PCV Valve Tag" for model "736C" only. Both list the proper application for the "736C" as 1966-1969 all with 427 except H.D., 1970-1972 454 except H.D. Should my 69 427/400 use the 736 or 746 PCV valve? Are the repro tag makers incorrect in their application? Thanks in advance. Chuck Gongloff #5629

[Joe L.]

Re: 69 Tripower PCV Valve

Chuck-----

As far as I know, all 1969 engines, except L-88, ZL-1, used the CV-736C PCV valve. This valve is GM part number 6423695.

Incidentally, although I almost hate to mention it, the configuration of the 736C valve changed slightly over the course of its long production run. Functionally, they're all the same, of course. However, there are slightly different "manufacturing marks" found on early valves compared to those of modern day origin. When someone first told me this, I didn't believe him. However, over the course of the last several years I've acquired a whole slew of these valves in the original boxes. The ones in the "old boxes" are slightly different than the ones in the "newer" boxes. If I remember correctly, it has something to do with little, dot-like indentions around the circumference of the valve. But my memory might not be the best on this one and my group 1 parts boxes are too deeply "buried" for me to get at them any time soon.

[Joe L.]

Re: 69 Tripower PCV Valve

Chuck-----

As far as I know, all 1969 engines, except L-88, ZL-1, used the CV-736C PCV valve. This valve is GM part number 6423695.

Incidentally, although I almost hate to mention it, the configuration of the 736C valve changed slightly over the course of its long production run. Functionally, they're all the same, of course. However, there are slightly different "manufacturing marks" found on early valves compared to those of modern day origin. When someone first told me this, I didn't believe him. However, over the course of the last several years I've acquired a whole slew of these valves in the original boxes. The ones in the "old boxes" are slightly different than the ones in the "newer" boxes. If I remember correctly, it has something to do with little, dot-like indentions around the circumference of the valve. But my memory might not be the best on this one and my group 1 parts boxes are too deeply "buried" for me to get at them any time soon.

[Gene M.]

Re: 69 Tripower PCV Valve

Interesting, Joe can you give us an update on the PCV's that are dotted when ya get around to it? Thank you

[Gene M.]

Re: 69 Tripower PCV Valve

Interesting, Joe can you give us an update on the PCV's that are dotted when ya get around to it? Thank you

[Joe L.]

Re: 69 Tripower PCV Valve

Gene----

Yes, as soon as I can do a little more research and also "dig out" my group 1 parts boxes, I'll provide additional information. In the meantime, though, lest anyone get the wrong idea, these earlier production 736C valves are by no means rare. Remember, the 736C valves were used in a WIDE ARRAY of GM cars and trucks in the mid to late 60s and early 70s. Many, many folks NEVER changed their PCV valves. Many, many of these 60s and 70s cars can now be found in wrecking yards. I'll bet I could go to any pick your own part type salvage yard and come up with 10 original valves without any trouble at all. No tools required for removal, either.

Since these valves really don't materially deteriorate, all one has to do is soak the valve for a day or two in Berryman's solvent. Presto! Just like new. My very first job which I got in 1963 when I was in high school was at a Chevron service station. We used to always clean these valves with solvent when we serviced cars; we rarely ever replaced one unless it was clogged to the point that it wouldn't rattle after solvent cleaning. If we could have soaked them for a day or two, I think even these valves could have been saved. Happy hunting!

[Joe L.]

Re: 69 Tripower PCV Valve

Gene----

Yes, as soon as I can do a little more research and also "dig out" my group 1 parts boxes, I'll provide additional information. In the meantime, though, lest anyone get the wrong idea, these earlier production 736C valves are by no means rare. Remember, the 736C valves were used in a WIDE ARRAY of GM cars and trucks in the mid to late 60s and early 70s. Many, many folks NEVER changed their PCV valves. Many, many of these 60s and 70s cars can now be found in wrecking yards. I'll bet I could go to any pick your own part type salvage yard and come up with 10 original valves without any trouble at all. No tools required for removal, either.

Since these valves really don't materially deteriorate, all one has to do is soak the valve for a day or two in Berryman's solvent. Presto! Just like new. My very first job which I got in 1963 when I was in high school was at a Chevron service station. We used to always clean these valves with solvent when we serviced cars; we rarely ever replaced one unless it was clogged to the point that it wouldn't rattle after solvent cleaning. If we could have soaked them for a day or two, I think even these valves could have been saved. Happy hunting!