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Messages - william

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Restoration / Re: 1969 Z28 spare wheel
« on: October 17, 2017, 04:03:29 PM »
Not nagging here but no one has seen every one of the 20,302 '69 Z/28s built. Over at the CRG we use the phrase "normative practice" to cover standard operating practices on the assembly line. That means production was configured to process uncoated Z/28 wheels. They were furnished raw, cleaned, dipped in black primer. The face of the wheel was painted argent. Did this process apply 100% of the time? No one knows but I doubt it.

I managed service replacement parts in automotive supply chain and if production needed my parts to keep the line going, they took them. In this case they ship from the same supplier. By November 1968 Chevy had more Z/28 orders than they could build and stopped taking orders. That tells me the plants were having a hard time keeping up. If the plants needed service wheels to maintain delivery schedules, it would happen.

Now that otherwise original cars are turning up with gray wheels, it looks like service wheels may have gotten into production on rare occasion. I have seen several grey AD and YH wheels in my days and assumed they were service parts. Maybe not. Wouldn't be the first time an original car was found to have 'incorrect' parts.

General Discussion / Re: "DZ" grease pencil mark
« on: October 15, 2017, 01:24:32 PM »
Here's a pic that has been around for decades. It's an engine bay photo taken at delivery. Enlarge it and it does appear there is something written on the end of the head.

There is a similar photo of an L48 engine in a Nova SS. Nothing visible on the cylinder head.

If this was done [probably] it was hardly visible. Did they always do it? Probably not.

Decoding/Numbers / Re: New to this site!
« on: October 12, 2017, 10:07:44 PM »
None of us was there, so when I started working on this I asked someone who was-John Z:

Yes, a body could be held (only in the Body Bank) for a full shift, and a sharp bank supervisor was always prepared to do that if he had to; however, the body was VIN'd  before it was released into the bank, so it was possible to see some pretty significant VIN offsets -vs. actual physical line position. With a nicely-balanced schedule, up to a six-unit difference wouldn't be unusual, and ten or twelve tells you that there had been excitement of some sort up in the Body Bank.

This is important because the last VIN of the month is the basis for reverse-engineering the calendar. If it so happened that the car selected as last VIN of the month happened to be significantly out of sequence, it messes up the calendar. It is possible that happened for the 1969 model year. Knowing the last VIN of a month also reveals the first VIN of the following month. For December 1968 last VIN-first VIN works out to 18,125 units. Divide that by 20 work days equals 906 units/day, within the plus/minus 6 VIN margin. However, that calculation does not work out that closely for every month.

As I stated, a work in process. Got another data point so more number-crunching.

Decoding/Numbers / Re: New to this site!
« on: September 26, 2017, 08:29:35 PM »
I have been working on 'reverse-engineered' 1969 production schedules for many years. Data used to compile this includes:

•   Chevrolet 'last car of the month' data for both plants
•   Known production rates of 57 cars/hour at Norwood late Sept ’68 through 1st week April 1969
•   Print dates on Van Nuys body & chassis broadcast copies. 
•   A very few factory to dealer invoices

Each of these sources requires interpolation.

The ’last car of the month’ VIN was recorded at the end of the 2nd shift on the last financial day of the month. It wasn’t always the last calendar day of the month. The successful completion of roll-test marked the car as complete. However, cars were not final-assembled in VIN order. The next car through roll-test could have an earlier VIN; on occasion several hundred units earlier.

People that worked at Norwood are emphatic about the production rate of 57 units per hour. It’s a simple calculation but requires knowing how many work days there were. Did they work only 1 shift on Christmas Eve? Did they work the day after Thanksgiving? For the most part it works out but on occasion requires making assumptions about overtime or shutdowns. It works for January ’69 if I assume production started on 2nd shift January 2nd and they worked a full Saturday the following week.

All bets are off after Firebird production moved to Norwood mid-April. They probably still built 57 units per hour; how they were allocated is not known.

It’s been stated many times but bears repeating: Body & Chassis Broadcast Copies were generated by Chevrolet Assembly after the completed body was received into the body bank. The date on them is when they were printed. Typically the date is a calendar day or two prior to completion.

Factory invoices are rare. The CRG was fortunate to locate almost 200 dealer copies from Norwood for the 1969 model year. There are two key dates on them:

•   Date shipped
•   Date of execution

The invoice from ZL1 #1 has been around for years. It’s known ZL1s #1 N569358 & #2 N569359 were delivered on Christmas Eve, 1968 from a 1989 interview with Fred Gibb. The date shipped on the #1 invoice is 12/30/1968, date of execution 01/09/1969. The date of execution is obviously irrelevant. In this case the cars were expedited, shipped soon after coming off the line. But in comparing almost 200 data points from the invoices to a production calendar, only 11% shipped the same day they were completed. 34% shipped the next day; 12% shipped 2 days later. That means 43% shipped 3 days or more after production; a few waited 11-12 days.

Conclusion: The “GM Official Production Date” on the NCRS report is from GMAC shipping info and is likely the date shipped. The actual production may be the same date but most likely is not.

I expect that some internal paper document for each VIN was time/date-stamped as the unit completed roll-test. However that data was not relevant outside the plant so there was no need to disseminate it. I believe dealers received reports on assembly scheduling, if not actual production. There are internal Yenko Chev docs around with columns titled ‘body build date’ ‘body comp date’ and ‘ship date’. Some are filled in; many are not. But the dates appear to be estimates; they show N578878 shipping February 7th when it could not possibly have been built by that time. Other close VINs shipped February 20th.

The production schedules will always be a work in process as more data is acquired. Lately, I only occasionally have to make adjustments it so it must be getting close.

Decoding/Numbers / Re: Caveat Emptor..too late for JL8
« on: September 25, 2017, 02:56:28 PM »
Still active on ebay.

Decoding/Numbers / Caveat Emptor...another tag mismatch
« on: September 24, 2017, 04:14:57 PM »


Car was final assembled on or about October 3, 1968. Ad shows an 01A [January 1969, 1st week] body tag with non-original rivets.

One or both tags are not original to the car.

General Discussion / Re: ebay 69Z buyer beware.
« on: September 20, 2017, 08:48:15 PM »
A little bit of knowledge is dangerous. Hard to explain how a car final-assembled around January 13, 1969 received an engine built 39 weeks later.

General Discussion / Re: Monza Red
« on: September 17, 2017, 08:23:45 PM »
Yup, black D90.

Pic way too big to post.

General Discussion / Re: Neat 69 Z/28
« on: September 17, 2017, 06:44:23 PM »
Car was ordered in May 1968 and delivered in November 68, 6 months...  is that possible ?

No. The number on the body tag is the order confirmation number. It was issued when Central Office accepted the order and put it in the schedule. The sequence started at 100001. Based the body tag number of 161652, this car was ordered mid-September 1968. At that time Chevrolet was flooded with Z/28 orders and gave dealers allocations to order against. Low-volume dealers were low priority and experienced delays.

The car was built on or about November 7, 1968. From order to delivery that's about 8 weeks. I've heard worse.

General Discussion / Re: Monza Red
« on: September 16, 2017, 03:35:53 PM »
Is this the L78 car that was at the Kenosha WI show Sept 2? Like to see a pic of the build sheet [actually Broadcast Copy].

There are no known production figures, even for RPO colors. Special paint can also indicate stripe delete or a non-standard stripe color. At the beginning of the 1969 model year black was an RPO color. It was soon dropped so some early black cars are special paint. It was brought back January 1969 as an extra-cost color; these cars are not special paint.

The only other Monza Red car I'm aware of was auctioned at Barrett-Jackson AZ 2013. It was a Z/28 with a Parchment vinyl roof and power windows.

Originality / Re: ZL2 Hood Grommet
« on: September 16, 2017, 12:53:19 PM »
The retaining prongs are part of a steel stamping so that part would also have to be duplicated. The rubber was molded over it. Rubber doesn't bond to untreated steel; rust is visible in the photo of the original. They didn't hold up very well.

The ZL2 grommet is similar to the speedo cable grommet [3792008]. The steel part may be the same; maybe you could obtain a supply of those and strip off the rubber. My guess, the part sold today is the speedo cable grommet.

Originality / Re: ZL2 Hood Grommet
« on: September 15, 2017, 10:14:33 PM »
Back in 1969 that grommet was probably a common off the shelf [COTS] part supplied by McMaster-Carr or the like. It's known as a 'witches hat' grommet because it was molded closed; the tip was trimmed to match the size of the wire.

What they now sell is as close as it gets; I doubt that's a reproduction. Even if you could find the original style there is probably a big minimum buy.

Restoration / Re: Reverse Lockout
« on: September 10, 2017, 09:45:41 PM »
Lock-out parts are different between automatics & 4-speed.

Only Muncies used the two-tab swivel mount & upper lock rod 3945599. Small-blocks use lower lock rod 3955773; big-blocks 3955776. Saginaw 4-speed parts are not the same.

The '69 Camaro Assembly Instruction Manual is a great reference.

Thanks, so is it safe to say
that since my frame has only
two of the theee holes threaded , that the car was a factory muncie car?

That and the Muncie-only speedo cable routing.

General Discussion / Re: Cross Ram 1968 RS Z28 at Mecum
« on: September 09, 2017, 03:21:41 PM »
Does anyone know about the Tripoli Turquoise 1968 RS Z28 that sold at Mecum - Pre-production or experimental Cross - ram and original Goodyear tires.  Sold for $90 k, surprised with those rare options that it didn't go higher.

Read the ad carefully. "Matching numbers" these days only means correct components. The entire drivetrain may not be original. No factory paperwork, no Camaro High-Performance certification. Is it really a Z/28?

The cross-ram was never an option.

Sold at Mecum Indy 2013 for $100k +10%. If that buyer just sold it, they had over $110,000 in it and cashed out for just over $80,000. Remember that when you see "will only increase in value" in an ad.

Restoration / Re: Reverse Lockout
« on: September 07, 2017, 12:40:09 PM »
Lock-out parts are different between automatics & 4-speed.

Only Muncies used the two-tab swivel mount & upper lock rod 3945599. Small-blocks use lower lock rod 3955773; big-blocks 3955776. Saginaw 4-speed parts are not the same.

The '69 Camaro Assembly Instruction Manual is a great reference.

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