On point #1 above: From two reports that showed 1969 model year production, both had 2 RPO ZL1 listed. If I recall, one report was through September 1969, and then the second report showed all of 1969 including the extended 1969 model year. Both reports showed only 2 RPO ZL1. These documents were sourced from magazine articles and previously published lists and were not found in the GM Heritage Center with the other trove of ZL1 related documents.

On point #2 above: That is what the internal GM documents from GM Heritage Center seem to indicate.

However, I think the second point is likely stronger: the internal GM documents indicated that "12-9-68" was the first "parts availability" date for an RPO ZL1 engine available at St. Louis plant for installation into a production Corvette. From what I understand, GM did not leave rare engines sitting around to be installed sometime well into the future, thus these documents seem to indicate the first RPO ZL1 was built on or slightly after 12/9/1968 given documentation shows that the Daytona Yellow ZL1 was definitely a RPO ZL1 and it was built in September 1969.

An additional important discovery in internal GM documents found at GM Heritage Center was that the type L88-engines were actually built with closed-chamber, despite the original CEC engineering plan for them to be open chamber (which was what appeared in various magazines in period). However, a "Stop Order" was placed on the open-chamber L88/ZL1 engine due to problems with the aluminum cylinder heads, which extended the closed-chamber models (including IT L88) for the 1969 model year way beyond the original engineering timeline. I don't have the data in front of me, but I believe this stop order was lifted sometime in the March 1969 timeframe, likely coinciding with the Camaro ZL1 engines released for "production" COPO 9050 Camaros starting with chassis #3. The first two "red hot" COPO Camaro ZL1s were requested by Pete Estes to ship out by December 31, 1968, for homologation/racing purposes and were not "customer" cars. As this was a production engine reliability issue for the ZL1, the lifting an engine stop order would probably have applied to Corvettes and Camaros at roughly the same time.

Additionally, the “427 CUBIC INCHES ZL1” console trim plate/badge (part number 3958746) was also marked on GM internal document Notice of Production Change C69-39 with the handwritten "12-9-68" date.

----Much interesting stuff! My 69 L88 that I bought with less than 3,000 miles from the original owner absolutely had open chamber heads. I haven't owned the car for many, many years but can't forget that as I removed the heads myself! One thing I can't remember was weather the production date was April or May of 69. I have multiple pics of that Monaco Orange convert, but did not retain any of the paperwork when I sold it to a Wisconsin collector in 1974-5.....Bill S

Im not a Corvette guy.
Believe this is a Prototype but I dont know if its a ZL1.
Sitting next to the Z/427 Camaro.
Someone posted these Pictures here on Yenko.net some years ago.

What's the deal with the windshield shape on that Corvette?

Looks to be a 70-72 nose, and odd treatment on the windshield. I don’t believe it’s the same car?

That C3 was a version done by Bill Mitchell. The windshield and mirror's are a giveaway. I'll search for some pictures I have, it's called the Aero Coupe.

Here's the Aero Coupe designed by Bill Mitchell. It was at Road America in Corvette Corral many times in the 70's. I believe it carried a ZL1 motor. I helped them unload it from the GM trailer one year, probably 1977 or 1978. I had my customized 1969 Corvette in the Corral and the driver liked it and asked me to guide him out of the trailer.

----Tim,,, One of my favorite Bill Mitchell concept Corvettes. I believe Ralph Eckler made a mold of that rear spoiler. Love the sidepipe covers!.....Bill S

Bill, what happened to that car? It sure was beautiful with lots of unique features.

in 1970, the Aero Coupe was reworked and renamed Scirocco.

https://i.postimg.cc/TYMzJy2Z/download.jpg

It received the slim, Manta Ray-style side pipe covers, got a new paint job with the front bumper-grille assembly painted body color, the mirrors were moved up the door pillars and the roof panel was given a rear view periscope. It had a ZL-1 all aluminum 427 C.I.D. engine coupled to a prototype 4-speed automatic transmission. For the next 4 years the car worked as the pace car at the Can-Am races.

https://i.postimg.cc/JzJtdHjZ/download.jpg

In 1974, the car was restyled again and was renamed Mulsanne. Painted bright metallic silver, the Chevrolet Corvette Mulsanne wore 1975 style front and rear bumper covers. The pop-up headlights were replaced with 4 rectangular lamps under body-fitting clear plastic covers. The hood had a raised center section with recessed, functional scoops on both sides. The interior was completely trimmed in leather with fixed seats and adjustable pedals and steering wheel. Chaparral style lace aluminum wheels were used.

The ZL-1 aluminum engine was bored out to 454 C.I.D. and was equipped with an experimental Rochester fuel injection system. Bill Mitchell called the Mulsanne “the greatest Stingray ever”.

That sure answers my question, Lee. I believe that gave that car to Bill Mitchell upon retirement.

----All the versions are cool, but I think I like the original version the best!.....Bill S

Bill drove many of the GM show cars on a regular basis - as long as they were street legal. In all the writeups, nothing is mentioned about him being given the car when he retired.

And not all of the show cars that he drove were Corvettes. This was his 1972 SD-455 Trans Am Firebird. The SD-455 became a production option in 1973. This is a 1 of 1 car. It's also the first TA with a "Screaming Chicken" on the hood

https://i.postimg.cc/xqVq002c/0.jpg

https://i.postimg.cc/TYbk2GmG/00.jpg

https://i.postimg.cc/v8JzNjKK/0.jpg

https://i.postimg.cc/fRZvwdDj/00.jpg

https://i.postimg.cc/7ZVnbLLv/000.jpg

https://i.postimg.cc/JhY3cdJP/0.jpg

1969 Manta Ray Concept

The 1965 Mako Shark II was sent back to the GM Design Studio for changes and was renamed the 1969 Manta Ray. William Mitchell, the head of GM Design Staff enjoyed deep sea fishing and had a profound love of nature. While on a fishing excursion, Mitchell was inspired by the manta Ray powerfully moving through the ocean, which inspired the Corvette Mako Shark II/Manta Ray “Stingray” styling “Dream Cars”. The Manta Ray sported more production realistic side pipes and twin rear-deck-mounted doors that popped up during hard braking to become reflective auxiliary brake lights.

Additional Photos:

https://www.gmheritagecenter.com/gm-...Manta_Ray.html

Looks like Randy Scism from MTI Powerboats took a page out of the Manta Ray styling.

There was also this prototype which was at the Pavilions in Scottsdale....once or twice


I think the other prototype was also at Pavilions as well-was discovered in Australia (I could be remembering wrong though?





https://www.1973-76transamconcept.com/history.html


Attachment 210500

Thanks for sharing! Love 1 of 1 factory prototypes and whatnot.

The article doesn't specifically say, but I believe it was design studio employee Paul Deesen that actually came up with the stripe package and taped up the car.

K

http://www.deansgarage.com/2012/gm-d...-sebring-1957/

At 8.55 minutes in this video, the person talking about this collection says this Camaro is 1 of 2 ZL1 street cars, whichi I recall being discussed in another thread on here:
https://www.youtube.com/watch?v=Y_Wc_m06pG8&t=554s

That's Al's old car, was an SS350. The clone build was documented on one of the early email lists back in the late 90's.
124379L510596

The ZL-1 9567 re-creation at BJ 2014

https://www.barrett-jackson.com/Even...REATION-162358

That VIN is different that what Kurt references above....so there are at least 2 ZL-1 clones that are black and gold?


from the BJ link above 124379L510204

We’re the original 2 from gm accounted for or destroyed. Just looked at a pic in Michael lamm’s the great Camaro book.

Per Chevrolet docs, only one ZL-1 show car was built. They made small styling changes during its time in the sun. Not known to exist.

Here's the car in a later iteration...at Pavilions in 2012. It just came up in my Facebook memories...They changed the front fascia and the rear window area to "make it" a 1976...



https://www.yenko.net/forum/showthre...99#post1578799

Arizona Republic
Phoenix, Arizona
Sun, Mar 2, 1969

This article lists, "perhaps 4 or 5 in existence".

https://i.ibb.co/510kyH5/img.jpg

Been researched extensively. Chevy 1969 Production totals show 2 built.

Production totals also say no 1967 427/425hp SS427 Impalas were made but John Hinckley got one brand new. GM Proving Ground engineer Dave Horchler told me he drove a '69 ZL1 Corvette that was new and it was not one of the two that exists today.

Cars
 

GM Production records and what GM Produced as prototypes or 1 off’s are different

There are:

- mules
- prototypes
- pilots
- production vehicles
- dealer conversions

GM production records unambiguously list two (2) 1969 ZL1 Corvettes ... a number which includes cars from only the pilots & production categories, nothing more.

The "total number rumored to be in existence" includes cars from all of the above categories.