Bob Boyette Z/28 JL-8

[Z282NV]

Cool story. Not sure if this has already been posted.

https://www.youtube.com/watch?v=yTnV-okOpPE

[William]

Impressed that they got the exhaust system right. Also, correct non-Z21 headlamp bezels and tail lamps.

Wrong master though. Always something.

[KevinW]

Cool story! He lived not too far from me :)

[travlnz28]

Thanks for posting. Great to see the original owner drive the car again.

Is the production number of 179 Z/28's out of the 206 JL8's produced verifiable?

[jl8z28]

My friend growing up had a fathom green69 Z28 when we were16 here in Baltimore back in 71 which made me like and want one they moved away and took the car to belmar NJ which is close to there, i ended up buying my 69 Z28 JL8 same build date from a guy in cherry hill NJ

[William]

Is the production number of 179 Z/28's out of the 206 JL8's produced verifiable?

It is the result of interpolating a monthly internal Chevrolet report [Trends] listing option sales by car line. Some of the options are further broken down by ECL, Exception Control Letter. Trends data is how it is known 997 COPO 9561 L-72 Camaros were built.

There were 4 ECLs for J52 Power Front Disc Brakes: AA AB AG AL. AG is the Z/28 ECL. As of September 1969, there were 19,014 Z/28s built, 18,835 cars with J52AG brakes. Those 179 Z/28s that didn't have J52 are assumed to have been built with JL8. That means 27 non-Z/28 1969 Camaros were built with JL8.

Despite what is seen today, most Z/28s were built with the standard production hood.

[x77-69z28]

I know it’s nitpicking, but I think the Camaro emblems on the fenders are too far back. It is a beautiful car, and a beautiful restoration. I have owned mine since 1978, and would kill to meet the original owner. I have been in touch with the guy I bought it from, and he swears he has some paperwork for the car. Haven’t seen anything yet!
Buddy

[travlnz28]

William,

Could the same procedure be done, or has it already been done, to break down production of the remainder of the JL8 cars. I would really like to know how many non Z/28 and SS cars were built with JL8.

[William]

There are only two known JL8 ECLs; 3.73 and 4.10 ratios. If there were others [likely], they were probably for other ratios.

Kurt's SS 396/auto was built with JL8, delivered to the Tech Center where it was likely removed prior to retail sale. Supposed to be a few other SS cars but no hard evidence at this time. Car and Driver magazine [August '69] ordered a SS-RS as a project, swapped the L48 for an LT-1. The car had JL8 brakes that were troublesome until Penske Racing made some adjustments. How it got JL8 isn't mentioned but listing the option price in the summary seems to indicate it was built with it. If it was, it would be the 1st known production JL8 car by a few weeks.

Still exists in excellent condition.

[KevinW]

Travlinz28's JL8 was discussed recently, I looked at the add, but no mention of rear gear ratio. But I would expect a 3.73 with a 307/Sag would not be ideal.

https://www.ebay.com/itm/334476363512?mkcid=1&mkrid=711-53200-19255-0&siteid=0&campid=5337851298&customid=538565&toolid=10001&nma=true&si=XSxXgzC4arQolmCDyuy%252Bxbby0ig%253D&orig_cvip=true&nordt=true&rt=nc&_trksid=p2047675.l2557

[Mr70]

Gregs' is a 3.07 12 bolt Posi.

QN 12-bolt 4.88 ~ Positraction w/4 wheel disc
QS 12-bolt 2.56 ~ Positraction w/4 wheel disc
QT 10-bolt 2.73 ~ Positraction w/4 wheel disc
QU 12-bolt 3.07 ~ Positraction w/4 wheel disc
QV 12-bolt 3.31 ~ Positraction w/4 wheel disc
QW 12-bolt 3.55 ~ Positraction w/4 wheel disc
QX 12-bolt 3.73 ~ Positraction w/4 wheel disc
QY 12-bolt 4.10 ~ Positraction w/4 wheel disc
QZ 12-bolt 4.56 ~ Positraction w/4 wheel disc

[travlnz28]

When the Ebay ad for the car was up I was contacted by a guy who claimed he knew my car and it was the last JL8 produced. According to the NCRS report it was produced on June 6th. Is there any way to verify such a claim?

[travlnz28]

William,

So the ECL's you spoke of were for the QX and the QY rear ends. Is there any way to find the ECL for the QU rear? I believe I remember Kurt saying that is what his car originally came with and that is what my car has.

[William]

When the Ebay ad for the car was up I was contacted by a guy who claimed he knew my car and it was the last JL8 produced. According to the NCRS report it was produced on June 6th. Is there any way to verify such a claim?

There are a pair JL8 Z/28s sold by Schukei Chev Waterloo IA, built approximately the same time. Cars were not built in exact VIN order so it is difficult to say. But typically, they weren't all that far off. N651702 [BDY 342866] N652055 [BDY 342865]. N652055 was owned by the late Warren Malkin, Jr. and was displayed at MCACN a few years ago. W/S is in Jerry's book.

The latest known JL8 car, a Z/28, was about 1,200 units after yours. There were just over 1,000 cars built last week of June at Van Nuys after the strike, possible there was a JL8 in that group.

We need factory paperwork or engineering records to learn the ECLs for the other ratios.

[fsc66]

CRG shows the QU rear as a 3.07 posi with 4 WHL disc brakes. Under trends report G80 option, there is only 1 3.07 rear axle listed with and ECL of TA, no?

Paul

[William]

The Trends report as of September 1969 shows G80TA production 5,595 units.

G80 ECLs are the same for JL8 and J52. ECLs for JL8 with ratios other than 3.73 and 4.10 are needed.

[BCreekDave]

Since the JL8 option was to homologate for TA racing kind of surprised in a way that there were no Firebirds fitted with it. I know the rules were sometimes adjusted on the fly like how Firebirds were raced with Chevy 302's. Maybe the same thing happened wit the brakes. Sorry if this is perceived as a thread hijack.

[William]

Probably because Chevy did all the R & D [$$] on the system and Firebird was viewed as a competitor. In production, Firebird used Pontiac-built rear axles.

The Van Valkenburg book Chevy=Racing? has valuable insight on the braking problems the T/A cars experienced. What they thought was severe brake fade turned out to be insufficient master cylinder fluid capacity under racing conditions. JL8 did not initially solve the problem. And, as it was designed for a lighter car, wasn't all that much better.

[travlnz28]

How were the ECL's for the 373 and 410 rears discovered? Can't the ECL for the 307 be found out the same way? Was it on the build sheet?

[William]

Factory paperwork. Window sticker, dealer invoice, shippers' copy. Don't have that info for other ratios.

[travlnz28]

William,

Sorry for the questions but trying to learn more as I kind of set this car aside until lately.

How is it that 206 is the absolute number? Reason I ask is that I talked to Wayne Guinn just after I found this car and he is the one who told me there were actually less than 206 built due to cost and scarcity of parts. Is there some factory documentation that supports 206 actual went down the line and out the door?

[William]

See post #6.

The Option Trends report was an internal Chevrolet document used for planning. It was not circulated outside Chevrolet.

That report states there were 206 1969 Camaros built with JL8 and you can take that number to the bank.

[Kurt S]

Several people have called the 206 number into question.
I've seen nothing to support that - all GM docs say 206.

[travlnz28]

Kurt,

What docs do you have for your JL8? Asking because of the earlier discussion about the ECL code for the QU rear.

[William]

Every Chevrolet production number you have ever seen likely came from those reports. In the late ’80s Len Williamson requested and received production information from Chevrolet for all Chevrolets built from 1953-1989. He summarized the reports in a book, “Tailfins and Bowties.”

It’s important to understand that the figures list production for equipment only when ordered as a discreet option. For example, it lists 116 1969 Camaros sold with CE1 Headlamp Washers. CE1 was included with Rally-Sport equipment; 37,773 built.

The reports also list production for each available engine, standard and optional. Surprise, no 427-engine listed for 1969 Camaro production. That is because the build records for COPO 9560 and 9561 Camaros lists the L78 engine; no ZL-1 or L72. Reported Camaro SS engine production [L34 L35 L48 L78] totals 35,998, 1,066 more than Camaro SS [Z27] production. That means actual L78 engine production was 3,823.

The report Len Williamson acquired for the 1969 model year was as of December 1969 and included the extended Camaro and Corvette production. Currently, no complete copy is known. Latest is as of September 1969.

[travlnz28]

So the example of 116 CE1 Camaros would be non rally sport optioned cars. Correct? 116 standard 1969 Camaros with headlight washers.

I take it this report did not breakdown the various rear end codes? Seems the choice of ratio and choice of positraction or not would have been a discreet option. I am probably missing the definition of "discreet" option.

[William]

Yes, the 116 CE1 equipped cars were not rally-sports. CE1 would be listed on factory documents for those cars.

The Trends report does list optional rear axle ratios. Again, only when a non-standard ratio was specifically ordered. Most Z/28s were built with the standard 3.73 axle but as an option [H05], only 1,916 produced.

[travlnz28]

OK. I guess it comes back to the fact that the ECL code for option H05 (373 rear axle) is known and the ECL for the 307 12 bolt posi with 4 wheel disc brakes is not known due to nobody having a car with the proper docs to discover it. And there are no known Chevrolet reports or documents that would lead to that discovery.

[Kurt S]

Every Chevrolet production number you have ever seen likely came from those reports. In the late ’80s Len Williamson requested and received production information from Chevrolet for all Chevrolets built from 1953-1989. He summarized the reports in a book, “Tailfins and Bowties.”

That is not correct. There are 2 reports.
The production totals that Len reprinted (he did not edit or change anything, they are exactly as provided by GM).
The Trends data, which is designed to highlight trends for future marketing and thus is organized differently than the totals.

Gregg,
My car has the POP. 05A car.

[travlnz28]

Thanks Kurt. Are you aware of any other car, besides mine and yours, that left the factory with a QU rear?

[LITTLE TOMMIE]

quite a difference of what it looked like when i first acquired the car and restored it like i wanted it by painting it rallye green and bring it back from the dead

[Kurt S]

Nope, just our cars. Though I've heard of one or two other low-po JL8's that probably had the ratio.