Do these 302 DZ Block Numbers make Sense?

[jmcbeth]

I purchased a stripped 302 block. Here are the markings:

- Block Casting #: 3932386
- Casting Date: E228 (May 22, 1968)
- Engine Production Code: V0913DZ (Flint ,September 13, Z/28)
- Partial VIN: 19N512382 ( Norwood, late September build)

These all seem reasonable to me. Are they? Did they cast the blocks that far in advance of the assembly dates?

Does CRG have any records of this VIN?

Thanks in advance,

jmcbeth

[Jerry@CHP]

John,

Do you have a photo of the staming?  Would like to examine.  I can tell you if it's a real stamping or not.  The casting date seems too early for that assembly date.  John Z, any thoughts on the gap from May 22 '68 until Sept 13 '68?

Thanks and happy New Year,

Jerry

[JohnZ]

That May-to-September span isn't impossible, but it's highly unusual; there was nothing special about that block - no reason for it to sit around for four months at either Saginaw Foundry or Flint V-8 when they were making 5500-6000 engines per day. Under NCRS Corvette judging criteria it would still get full credit since it falls within the six-month "window" prior to the car's final assembly date, but it's not what we'd call "typical", which is 2-4 weeks prior.

[jdv69z]

Is it 4 bolt main? Wouldn't that qualify it as 69 model year? Or could that have been modified/added? 68 was 2 bolt correct?

Jimmy V.

[jmcbeth]

Yes, it's a four bolt main. I don't think that two bolt mains could be turned into four bolt mains.

Jmcbeth

[rich69rs]

- Block Casting #: 3932386 came in both a 2 bolt (327) and 4 bolt (302) variants in '69.  Same block, different machining processes.

[jdv69z]

So if is not an original 302 block then someone took a 327 block, added 4 bolt main caps, (are the 4 bolt caps dated somewhere) had to  machine, drill and tap for the 4 bolt caps, and probably align bore? Then machine the pad to re-stamp with partial VIN and DZ markings? All this to sell a bare block for a profit? I don't know how much was paid, but it doesn't seem worth it to me? I vote for it being legitimate.

Jimmy V.

[rich69rs]

http://www.camaros.org/forum/index.php?topic=943.0

Above link contains a response from JohnZ re: factory mchining of 2 bolt vs. 4 bolt applications for the same block casting #. 

[jdv69z]

I read the link regarding machining of 2 versus 4 bolt main blocks at the factory. Does it not make sense that as soon as a block (or any part for that matter) is machined or changed that it then becomes a different part no.? So the part no. on the block is for the raw casting only, and as anything is done thereafter it becomes a different part. A machined block with 4 bolt main would be a different no. than the same block machined with 2 bolt mains. For identification purposes at the factory, they made have had a sticker or tag with the applicable part no., 4 or 2 bolt. Or a least some type of job no. Surely they did not rely on visual identification to distinguish?

Jimmy V.

[JohnZ]

No sticker or tag was necessary, as it was machined with the caps in place, and visual ID is simple between 2-bolt caps and 4-bolt caps by guys who build 300 engines per hour all day long. When the finish-machined and cleaned block arrived at the first station on the assembly line (air-gaging the bores), the suffix code for that particular engine was written on both sides of the block in grease pencil so the assemblers further down the line knew what internal components to install in it, and the stamper knew which gang-stamp holder he needed for that engine.

[jmcbeth]

Everyone,

Great dialog! I have learned quite a bit.

As requested by Jerry, I sent him pictures of the stamps and date codes. He replied verifying the block is a real Z.

Still can't explain the date gaps, however. Someone told me that there might have been a strike during this period (May, 1968 and Sept, 1968), but you would think this gap would be much more prevalent in blocks that were produced then. Perhaps the bock needed some rework?

Anyway, now that I know it's a real deal (whew!), off to begin the rebuild process.

Thanks to everyone who contributed.

[Jonesy]

That block was for sale on camaros.net awhile back. I have a picture of the block stamping.
I can send it to someone if they want to post it.

[Jerry@CHP]

Yes, this block is the real deal.   

Jerry

[zbo2]

jonesy...
can you e-mail me a pic of the stamping for my files.......
zbo2@comcast.net
thanks
Joe

[lcmc]

I have the same type of spread with my dates. Block casting date is F 5 9 and assembly date is V1015DZ. It is a 3970010 block and the VIN on the block is 19N705488. I just have the engine so if someone has that car let me know. Anyway what are you thoughts on this date spread?