1969 Z28 Exhaust Beginning of Resonator's

[Bryan302]

I have been researching the information available for the start of resonators on 1969 Z28's.  I have an 05A Z28 in the 640XXX VIN range.  My car was built on May 07, 1969!  Did it have resonator's?

According to the recall letter, stating that Z28's produced from Dec. 4, 1968 until May 02, 1969 incorporated a regular muffler dual exhaust without resonators.

According to the price increase from $506.60 to $522.40, was this increase just for the chrome tips or resonators and chrome tips?  I've seen examples of window stickers of VINs into the 641xxx range, still with a price of 506.60.  The price of $522.40 was well into the 649-650 range.  From my research, 05A ended close to 6442xx and 05C started around 6448xx to 6449xx.

My point or question is... If the charge for chrome tips was the increase, where is the charge for resonators?

If the price increase didn't start until the 649 - 650 range, then it looks like cars built through 05C didn't get resonators or GM gave them away??

I have been keeping up with Box 198 on the Chassis BC also.  It seems that FM was used up to around the 05A range and FQ started with 05A and 05C.  Are there enough examples of CBC to reflect that FQ might be with resonators?

My concern for this whole episode is this.  If our car is built on or after May 2, 1969 and it is within this transition, will it be WRONG without resonators, or recognized as a borderline?

Thanks,
Bryan

[william]

The CTSB I have states the new Z/28 system will be effective in production approximately April 15, 1969. With the 2nd recall, the Z/28 system was now the same one used for the L48 300/350. Parts were already there; just a matter of having adequate supply. There is no mention of a price increase for the new system. When chromed tailpipes became standard May 19, 1969 N10, SS and Z/28 pricing increased $15.80. The earliest FQ system I have is 05C; take that with a grain of salt. Not nearly enough data.

If you're looking for approximate VINs I'd estimate N627600/L52900 for the resonator system; N646229/L530160 for chrome tail pipes. The few remaining OE production chrome tail pipe systems still in existence show an interesting difference. The RH tail pipe was the new design 2-pc chromed version, welded to the muffler. However the LH tailpipe was the standard part polished and flash-chromed. This was used at least through September 1969. I have had several NOS service chrome tailpipe pair and both pipes were 2-pc.

[Bryan302]

Thanks William,  The earlier release than May 02 is kind of surprising.  One would think GM would not want to spend money unnecessarily, and release parts as early as early April with 04C and possibly 04B cars.  The 627xxx range would definitely be 04C range and more than likely earlier than April 15th.

I have a strong feeling that FQ means with resonators and not chrome tips.  Here's why.  I have seen several examples of CBC's that hit about the right time frame for the transition, and they are an 04B LOS RS Z28 with FM, 04C LOS Z11 with FM, 05A LOS Z28 with FQ, 05C NOR Z28 in 645xxx range with FQ.  These last two are the fuel for my fire.  Chrome tips were definitely not out yet.  Is there any way to inspect the CBC's in the DB to see how they compare??  My curiosity is out the roof!  It seems to me that, if there are more with FQ before the 645-646 range, then it would be extremely likely that FQ means resonators.

Did LOS and NOR plants have this transition going at the same time?

Are there any living examples of 04B or 04C Z28 survivors with resonators?

Thanks,
Bryan

[william]

Exhaust is only specified on the CBC and those are very tough to come by. Typically they were in the car as delivered to the dealer and discarded; some dealers put them in the folder with other paperwork. I have a few copies; our db just lists it if it was present. The latest FM example I have is 2nd week of April at Van Nuys so I believe you are correct about FQ indicating resonators. I expect the change was simultaneous at both plants.

Chevy was vague about the date for the transition to the resonator system because it did not involve a price change. They likely used up remaining stock, then changed over. The change to chrome tail pipes had to be coordinated with pricing. I'll bet Production Control people were on the line days prior, removing the standard tailpipe systems.

I'm sure there are a few survivors around with OE resonator systems; just don't happen to know of any. Exhaust in those days didn't last more than a few years.

[69Z28-RS]

Related to this question is the *last known Z28 with chambered exhaust (as an option)*...  Do we have an approximate date for that change (when chambered was eliminated as an option?).. 
The CRG only states 'May'...  ie.
"Chambered dual exhaust was initially standard on Z28, L34, and L78, but was made optional in November 68 due to noise restrictions (also available on COPO cars), and was finally discontinued in May 69."

[william]

Chambered was discontinued as an option on May 19, 1969 same day chromed tailpipes entered production. So the same VINs may apply; last NC8 cars were prior to N646229/L530160. Vehicle orders still in process were built with the standard N10 system.

GMPD continued to service NC8 for several years. I bought a complete system at a dealer in 1976.

[Steve Shauger]

Just an FYI, but a July built L78 Chevelle survivor has been documented (build sheet), with chambered. Although this is not a camaro, chambered exhaust on the chevelle was still used after May 69.

[Mark]

LOS was shutdown on April 29th 1969, so if you have any LOS sheets from 05A they come from cars physically started during the last week of April 69, and finished in June or July.  Wonder when the CBC was printed at LOS in a GMAD plant, day 1 of assembly, or somewhere later dwon the line?

[william]

Just an FYI, but a July built L78 Chevelle survivor has been documented (build sheet), with chambered. Although this is not a camaro, chambered exhaust on the chevelle was still used after May 69.

The May 6, 1969 letter announcing chromed tailpipes and the discontinuation of NC8 is specific to Camaro.

This may be a good time to clear up decades of confusion about how the chambered recall affected L34 & L78 production. As of the initial recall in November 1968 those vehicles were built with the standard N10 resonator/muffler system. The interim system w/o resonators was Z/28 specific and prompted the second recall. Undercarriage photos of ZL1 #3 N608193 when new show it was built with the standard N10 system.

[Bryan302]

William, thanks for your help!  I will continue my research on this subject.  You have helped greatly.

Mark, that 05A LOS Z28 FQ came from a thread on TC about Box 198.  That one example may be the closest to the transition from FM to FQ known.  I would love to see more CBC's of that time frame.  I'm also curious if FM has showed up on CBC's after the first of May?

Gary, The window sticker example in Jerry's 69 book for 9N641676 may be one of the last factory NC8 cars known before the 646229, May 19 cutoff.  I would like to know of a later example.

Thanks,
Bryan

[william]

ZL1 #59 N642876 was ordered with NC8. Final assembled on or about May 13, 1969.

[Bryan302]

Sorry William, I meant to say 641676 was the last known Z28 with factory NC8 before 646229.  Still nice to know about the ZL1 too.  I was tying in to Gary's statement several post back about Z28's with an option of NC8.

Thanks,
Bryan

[al8apex]

In order:

[watk69]

I have N638663 that was fitted with a Gardner exhaust with chrome tips and no resonators and has been judged 3 times and never been dinged for it at MCACN and Vettefest. But I bet it would get dinged for Legends judging by ACA. Be nice to know what is correct.........definitively

[william]

That is an oversight on the judges part. The dates for each are established. N638663 was final assembled on or about May 6. It should not have chrome tailpipes and should have resonators.