Z/28 engine pad stamp codes..

[dutch]

Was reading some stuff on a Facebook discussion regarding 1968 (all 3 years of 1st gen actually) Z2/8 engine code stamps, and someone came up with MI after all of the regular MO, MP, and DZ, codes were mentioned.
Apparently they claim the Estes' Z convertible has an MI code assigned to the 302 block and they claim that proves it is a valid code for Z2/8 engines thusly.
Firstly - does this 'one vehicle' in fact have an MI code stamping and does it have a regular 678 engine block casting number??
Secondly - we all know this is a valid, yet oddball vehicle. Should it in any way be considered a 'production vehicle' or one that should hold any significance as a valid type or model for the 1968 production year?
and..
Thirdly - some have commented that this particular car is or should be considered a COPO car since it has this MI code and in fact are saying that MI is a code designated for a COPO vehicle by GM?

I would love to hear any thoughts regarding this particular car - and it's unique code or designation if in fact MI is truly the stamp on the engine block.
I personally consider this car can't or shouldn't be considered a COPO because it wasn't ordered through the dealer or COPO system - instead it was probably concocted as a on-off or test vehicle status considering it was the only example made, and that it probably like many was probably slated and destined to be crushed at some point like many other 'test vehicles' GM made for evaluation and then finally destroyed after a point, never truly considered to be a long term car for public sale..
All comments and/or details shared are greatly appreciated!
Randy.. 
   

[william]

The Estes '68 Z/28 convert lost its original pop when it was sold as a used car December, 1968. Fortunately, the transfer form has an imprint of the original. I also have a copy of the manually-typed Car Shipper; not ordered on a COPO.

Just internet BS.

[cook_dw]

So are you sayin' don't trust what you read on facebook!!??!!?  But those guys are experts!   

[MO]

It's stuff like this that makes me thankful that I couldn't care less about being on Facebook.

[dutch]

So are you sayin' don't trust what you read on facebook!!??!!?  But those guys are experts!   

I truly must admit that I am amazed of how much misinformation people post and you can almost see how the bad info, if it fits someone's narrative gets propagated and soon becomes the 'truth' on places like Facebook.. even in their Camaro owners section..
All it takes is one guy to say something off the wall and soon there are others with even further off the wall info to gladly share - and off it goes!
I must admit I get involved occasionally when I can't read any more falsehoods and chime in - but I try and keep from commenting just because I know eventually some 'expert' will chime in and try and make me look bad for trying to contribute some logic to an exchange.
I knew very little about Estes' covert or the codes involved - that's why my initial post here - but before I got back to share what you fellows had offered up in the way of info on it - it seems to have taken on a new life of its own and now not only are MI codes are solid proof of Z2/8's but apparently now also of COPO status..
I give up!
Thanks for the Estes' info - I'll have to try and dig deeper at some point and learn more about it - just for my own interest and information..

[z28z11]

It's stuff like this that makes me thankful that I couldn't care less about being on Facebook.

I'm right there with you. I view social media like most of the media sources presently - with a grain of salt.

Great response, William - I should have known the CRG had tabs on the Z 'vert.

Now, if we just knew who had the black/gold ZL-1 shown in the design staff center in Lamm's book - or if it still exists.

Regards,
Steve

[william]

There is much mis-information out there concerning the '68 Z/28 convertible. At one time, it was claimed to be the catalyst for many of the Trans-Am racing parts such as 4-wheel disc brakes and the cross-ram. All nonsense. The chronology of the concept, design, development and availability of the cross-ram intake and Corvette 4-wheel disc brakes is available in an excellent book written by Wayne Guinn “Camaro Untold Secrets” many years ago.  Development work on 4 wheel discs began very early in 1968 as evidenced by several Chevrolet engineering drawings dated January 1968. It was released as an off-road part March 1968.

Development work on the cross-ram intake began late in 1967. Documents discussing a dyno comparison between the stock 1 x 4 system and a fabricated 2 x 4 system are dated August 8, 1967. The earliest production-type manifolds had casting dates of October 21, 1967. The cross-ram was released at the same time as the 4-wheel disc brake option; the instruction sheet is dated March 20, 1968. 

Both of these new systems were featured in the May 1968 Hot Rod magazine in an article titled "Just For Fun: 68 1/2 Chevys". Car & Driver tested a cross-ram/JL8 '68 Z/28 in the July '68 issue. Magazine lead times are about 3 months; these events took place during March, 1968. 

The Estes '68 Z/28 convertible was built during the 4th week of July 1968. Documents from Chevrolet indicate it was placed in service July 24, 1968. There is no way this car, built 4 months AFTER the release of 4 wheel discs and the cross-ram, had anything to do with them. It was allegedly retrofitted with a cross-ram and 4 wheel discs for display at race tracks hosting T/A races later in ’68. That equipment was not on the car when it was sold December 17, 1968.

There is no question of its historical significance to Chevrolet and Camaro enthusiasts. All evidence indicates it had no involvement with the concept and development of these famous racing parts.
 

[Gars68Tux]

MI suffix code for 68 was an LF7 with TH350 (late year test fleet).

[Gars68Tux]

1968 Camaro Engine Application Suffix Codes
                       Automatic      3- or 4-speed
                      Transmission    Transmission
                      no-A/C  A/C     no-A/C  A/C 
                      ------ ------   ------ ------
 230ci/140HP base L6    BF     BH       BA     BD
 250ci/155HP L22 L6     CQ     CR       CM     CN

                        Automatic        Manual
                       -----------     ----------
 302ci/290HP Z28           --              MO
 327ci/210HP base V8     ME & MI*          MA
 327ci/275HP L30         EE & EN*          EA
 350ci/295HP L48         MU & MF*          MS

 396ci/325HP L35           MY              MW
 396ci/350HP L34           MR              MX
 396ci/375HP L78           --              MQ
 396ci/375HP L89           --              MT

 * Engine code with TH350 transmission, used in
   late-year 1968 TH350 test fleet

[KurtS]

Correct. MI would not be a hi-po.

I tire quickly of facebook. Untruths spread rampantly.

[x66 714]

Correct. MI would not be a hi-po.

I tire quickly of facebook. Untruths spread rampantly.

Yep. Even when you prove to them the truth, they're still a know it all...Joe

[dutch]

Thanks for all the responses here..
As I stated I would like to learn more on the Z convertible and will when I have more time to do so at some point.
Yep - Facebook is a Hell of a place to try and inject some (Any) logic as it seems as soon as you try and add some into a discussion, out pops another theory or "my friend's Dad had one" ism and away the story goes off the rails, or in a completely different direction all over again.
Its the reason I rarely ever get involved, but when I do I'm quickly reminded that I promised myself never to do it again after the last time..
Thx again for the info and time..   Randy