Plant Date Code
- Thread starter jiho2
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wantattype2
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- Sep 24, 2010
If you're talking about the picture I posted, I don't believe that can be. Since this is the original block out of my 86 GN.
I only have some guesses, so here goes. All the way to the right it says 3.8L , next to that are an uppercase D and an uppercase N with a littlep pointer pointing to N (night shift???) Next to that is a circle of raised dots, 11 of them with a break and a pointer pointing at the nineth dot (9PM????). Don't know what the big 2 might indicate, or the funny looking wheel with the P next to it.
Not too sure about the J125, but maybe it means "Julian 125" Julian date = 125th day of the year???
This is of course all purely speculation.
Not too sure about the J125, but maybe it means "Julian 125" Julian date = 125th day of the year???
This is of course all purely speculation.
No need to get huffy about it.
No actual huffiness intended. More like poking the cage with a stick.
Anyway, thanks for the reply.
Unfortunately, none of the markings in your pic is a stamp, they're all cast-in.
The one at the bottom (J125) is the Block Casting Date code, which I believe also appears just in front of the starter mounting pad. Yours decodes as October 12, 1985 (J = 10 = Oct). That's when they broke the mold to cast your block.
The Plant Date Code supposedly has more information -- where and when the complete motor was assembled, and the type code. And supposedly it was stamped somewhere -- like the VIN. It supposedly has the format P1234ABC, where:
P = 1-letter plant code (eg, F = Flint)
1234 = date (12 = month, 34 = day)
ABC = 3-letter engine ID code (eg, your '86 would be FAC)
That's what I'm looking for, and I'm beginning to wonder if Buick actually put it anywhere, other than printed on a paper sticker.
That paper sticker has the date (even the time of day) and the engine ID code, but doesn't have the plant code. It also isn't formatted like the Plant Date Code, and most importantly, isn't stamped into the block like the VIN. (I guess a paper sticker is a kind of stamp, like postage, but not what we mean.)
Where is that sticker on your block, though?
It must be the sticker, because I can tell you for sure after going over my block with a fine tooth comb, there are no other "stampings" on the block. All block markings are cast, the vin being the only stamping on the block.
wantattype2
Member
- Joined
- Sep 24, 2010
This sticker is on the drivers side head behind the assy bracket.
Er, I think I made one small mistake here. I believe GM left "I" out of these alphabetical sequences (to avoid confusion with "1"), which would make J = 9 = Sep, and your date would be September 12, 1985.
Correct me if I'm wrong about being wrong.
Could very well be. I've heard rumors to that effect. I think I may remember seeing an unreadable remnant of a sticker there.
And that's precisely why they were supposed to stamp the metal. The Buick parts catalog itself describes this stamp, and refers to it in at least one place I can think of, saying extra letters were stamped near it to indicate a mid-model design change.
And that's precisely why they were supposed to stamp the metal. The Buick parts catalog itself describes this stamp, and refers to it in at least one place I can think of, saying extra letters were stamped near it to indicate a mid-model design change.
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