My Z arrived today!

[BULLITT65]

Here is Jerry's report on the car from 2007.  Some of the items have been fixed.  Going back to the axle comment regarding the C before the BU....why did he not mention in the report?  I would assume that some were stamped with the C and others not for whatever reason.  Has to be some deviation for human element?

Well not according to the "human element" putting together the thread on rear axels.....

[69Z28-RS]

No, I don't think any of us have seen (yet) any protecto plates with the 3 letter prefix on the rear app stamp.  The three letter (with the C in front) began with the '70 model year (apparently), yet some of the late '69 Camaros have a 'C' stamped out front.   It would be interesting first of all to find a '70 protecto plate with the C on the rear and on the protecto plate!   I think Charley (clil) has a very original '70 Z28 and perhaps he would be kind enough to check/verify that fact?

Given that some of the late '69 diffs have the C stamped out front, Can we find one that also has an original protecto plate with the 'C'.

Note:   Since you are fairly new to CRG, you should check the thread re the rear ends, as sometime in August, the rear carrier casting number changed, and nearly simultaneously with that, the 'C' began to appear.  Bryon is collecting data from late '69 cars  in attempt to document those changes.

[rspallina]

Thanks Gary.  I would be curious to see the designation on a late 69 protecto plate or on the 70's.  I did read the thread but there seemed to be some question about whether or not the C was on every car produced late august and later.  I understand there are not a whole lot of data points but it does appear that the C did start showing up on some cars when they went to the 341 rear end.   

[BULLITT65]

Well I have tried zooming in on the image, and all i can make out is bumpiness or surface rust of age. It would have to be a very very light C stamp to be hidden in there IMO.

[rspallina]

When you are under the car you can see it at certain angles...very difficult to get a pic...let me know what you think about this shot that my 11 year old daughter got after scrubbing a bit with a sponge:

[bcmiller]

That is a C BU stamping, as I would expect.  But very light.  No problem that it was not mentioned in Jerry's report.

I doubt you will find a POP with CBU stamped on it.  I have some data on early 70 model year cars with the 3 letter axle code.

Everything on your car agrees with the data points in the axle thread.

[bcmiller]

BTW, here is a pic of the casting date on the axle that I took this morning...Jerry wrote in his report "1":  Is it possible to expose more of the stamp than what is there?

Unusual axle casting date, did you show the casting number or list it somewhere?  I assume it is a 341 casting.

[rspallina]

Bryon - Jerry lists it as a 341.  I have looked at the drawings of where it is supposed to be but not sure I am looking in right place.  I need to see a proper pic of where I can find the casting number.

[bcmiller]

OK, 341 casting, that lines up just as expected.  Since you had to clean the area where the C is (and it is still very light) it's not unusual that Jerry did not mention it.  Note that the C is spaced over from the BU.

Casting date is unusual but not a problem.

I posted my reply in your message above by mistake, then removed my reply and posted it here.  That is why it shows your post above as modified.  Sorry.

[rspallina]

Here is the cast date that Jerry listed looking at the 10:00 position and not the 2:00 position which is where you need to look for a 341 rear end according to his book ( he may have been rushing).  Before I read the note in his book I was looking at 10:00

[bcmiller]

Rob,

I tried looking at the casting date several different ways.  What is there could be I 7 - with the 9 missing.  That would be cast September 7, and with the assembly date stamp of 0910 (September 10) it would make sense.  But there is no doubt in my mind that the axle is 100 percent original to the car.

[rspallina]

Thank you Bryon. I posted the axle info on the appropriate thread so you can add to other data.

[69Z28-RS]

Rob,  your 'C' was difficult to spot, just as mine was, but after your cleaning and new photos, it seems to be there!   I think that 'C' wasn't intended to be placed on 1969 model year cars, but happened to the late production cars as a change due to the 1970 model change to the rear application notation.   It's just one additional thing that is different (or special?) about our 'late '69 cars'...

[69Z28-RS]

Rob's 'C' seems to have taken some 'licks', just as mine had.   It makes me wonder how those extraneous rocks that hit those 'C's .. always hit the C rather than the B, U, etc…?...      OR maybe the diff factory put those 'C's on the rears – of the late 69's, and then decided to 'remove' them, and banged them up at the factory intentionally?   (I think no one knows the real story or reasons for that – management made an unprecedented decision to continue production of '69 Camaros and Corvettes for an additional 5 months… so obviously things were in flux and decisions about '69 vs '70 issues made quickly ...)..

Rob's 'C' has the same relative spacing before the BU as mine does… almost all the 69 rears with the C.. the C is displayed a couple of character spaces to the left of the 'BUxxxxGy' code.. it's almost like they didn't want it to be considered part of the app code?   Is the 'C' used on 1970 3 letter diff codes displaced the same way?  Or are they closely spaced as if stamped at one time?  

PS. Why don't we consider the 'E' as part of the app code as well? ...  


++++++++++++++++++++++++++++++
Another case of me being in a hurry and trying to quote your post, but ended up editing it.  Sorry about that Gary, post your pic with the C circled again if you want.  I am between being at work and another function.  I should know better than trying to rush a reply.   My apologies...

[bcmiller]

Gary, I will address those questions later today hopefully (very busy day ahead).  

Axle plant was changing over to 3 letter codes, Camaro production ran over is the short answer.