PCV

[Lyndon S.]

Is the #CV736C PCV right for a LS-5 car? And the #CV746C is a LS-6 car or is it the other way around? Also or both still available from GM?
Thanks

Kelly

[Gerard F.]

Re: PCV

I just saw the CV736C for sale at ACDelco Parts online. Bet that guy that paid a $1000 for one on ebay is kicking himself.

Jerry Fuccillo
#42179

[Joe L.]

Re: PCV

Jerry-----

Yes, the CV-736C valve, released in 1966, is still available from GM and Delco to this day. There are some "nuances" that have changed, though. These include the script stamped on the valve, the letter on the bottom of the internal valve, and the number of "indentions" which surround the perimeter of the valve at the base.

The same thing holds true for the CV-746C which also remains available.

The CV-736C is the valve used for all 1968-72 Corvette engines EXCEPT L-88, ZL-1, and LT-1.

[Lyndon S.]

[Gerard F.]

How about the CV-726C for a 67 327/300

Joe,

The reason I know that the 736 is available through AC Delco is because I was searching for a 726 for a 67 base engine. AC Delco keeps coming up with the 736 which is the wrong configuration for my car. The 726 is the one which is threaded to the oil fill tube.

The one I have on now says "AC Spark Plug" over "Type CV 726C". Don't remember ever changing it, but cleaned it up when I couldn't find one in the past.
I see that Paragon has a 726C PCV listed but wondering if it is exactly like the originals.

Do you think I have a $27 repro, or an original or older service replacement.

Jerry Fuccillo
#42179

[Joe L.]

Re: How about the CV-726C for a 67 327/300

Jerry-----

The CV-726C was discontinued many years ago----from memory about 1990.

The reproductions have not been around too long so, unless you installed it on the car yourself, I very much doubt you have a reproduction. Most likely, it's an original valve or an earlier SERVICE valve. There's no difference, at all, between an original valve and earlier SERVICE valve. In fact, I don't think there's a difference between the original valves and later SERVICE valves.

Cleaning these valves is very easy. Years ago when I was in high school and worked part time in a Chevron service station (my only employment EVER in the automotive industry) we used to clean these valves with every lube and oil change. We used Berryman's B-12. I still use it today and it still works just as good.

[Duke W.]

Re: How about the CV-726C for a 67 327/300

Wow, you guys were thorough!

Even though most GM recommended maintenance schedules say to replace the PCV valves every 30K miles or whatever, those old all-metal valves really don't wear out and periodically cleaning them in a mild solvent like mineral spirits will usually keep them in good working order indefinitely.

If they really get gunked up soaking them in carburetor cleaner will usually get them squeaky clean.

Duke

[Phil P.]

Re: How about the CV-726C for a 67 327/300

joe,my 67 L71 valve has the rochester script along with the 736, it has an M on the down side of the valve and what appears to be 8 stake marks around the base---also remanents of an orange tag where the hose attaches---is this a service unit of later date or ??? thanks---phil

[Joe L.]

Re: How about the CV-726C for a 67 327/300

PHIL-----

Definitely a later SERVICE valve.

[Gerard F.]

Re: How about the CV-726C for a 67 327/300

My 67 owners manual says to change the PCV valve every 12 months or 12000 miles.
It was changed at the dealer 12 month check according to the warranty booklet, but since I've had it for going on 39 years, I can't remember changing it. Remember cleaning it with carburetor cleaner.

So I don't have the original, but I have the second one

Jerry Fuccillo
#42179

[Joe L.]

Re: How about the CV-726C for a 67 327/300

Jerry-----

I strongly expect that any valve replaced that early would be identical to the original in every way. Like I mentioned previously, I even think that the later SERVICE valves were identical.