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Casting Date

GM Guy

GM Guy

Manual Trans. 2WD Enthusiast
Messages
4,838
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846
Location
NW Kansas and SC Idaho
Hey guys,

I have a casting question.

The motor in question is a GM Goodwrench, so there was slight hope that she is an optimizer, but after these pictures, I dont think so.


I would still like to know what year this actually is, so any help there would be appreciated!



100_0628.jpg 100_0630.jpg100_0632.jpg100_0634.jpg

picutes 1-3 are the castings, picture 4 shows the donor, and the hoarding problem my old man has! :)
 
the second picute, if you cant make it out, says: GM-D with a little pie logo in front of it. that is near the OPS. the two rectangles at the right are about the only thing I saw under the IP, so even though there wasnt anything as far as GM markings on the front or back of the block, like some folks mention should be there, I still feel that since I cant find a navistar logo, along with the GM-D marking, I think she is a late 506 GM casting.

also, JR savoie, if you read this, this is the truck I am thinking about parting out some more. I an still on the fence, due to it having a 5 speed, but if I do kill it, is this your paint color? also take not of the extra flares and runing boards screwed on, and the fender and door interference damage.
 
IIRC the gm stamp makes it GM, Navistar didn't use it in their casting.
 
Looks like it is in too good of shape to part out. You should see my truck!
 
NVW said:
IIRC the gm stamp makes it GM, Navistar didn't use it in their casting.
Click to expand...

yup:

accf02e9.jpg


Leo's on the money.

Since it's a GM casting, there should be a date code on teh upper face of the trans mounting surface in pic number three that will break it down to year, month and day...
 
My navistar/optimiser doesn't have GM anywhere on the block itself, but does have GM cast into the main caps. FWIW
 
so your saying the code on the bellhousing lip, same orientation as pic 1, but to the right, is what tells me the year?


EDIT: just ran out to the shop in pajamas and slippers. :) the code on the right side of the bellhousing lip, to the right of pic 1, above pic 3, is: A159
 
That is a GM date code. Block was cast on Jan 15, 1999. AMGeneral changed the date code on the blocks they cast. It will be 2 numbers then a space, then two more numbers followed by a letter. For example my block code is 10 04 J (Month, Day, Year). The years start with H for 2001, skip I then J for 2002, K for 03 and so on. The first "enhanced GM blocks" were supposedly cast starting on C159.
 
so what is the A about? does that mean january? so the slightly better GM motors began to be cast in March of 1999? If so, to make sure I have this correct, a B128 is a february 12, 1998 block?

and then back to the optimizer, is there a space between the second number and the letter like you have typed, or is the only space between the first and second number?
 
GM Guy said:
and then back to the optimizer, is there a space between the second number and the letter like you have typed, or is the only space between the first and second number?
Click to expand...

Two spaces, just like he typed it.

MONTH..space..DAY..space..YEAR CODE
 
this is the truck it is going into:

100_0028.jpg100_0026.jpg100_0027.jpg



I am still wondering about whether or not this old girl deserves a project thread, what do you guys think? :)

She is a 220K miled C2500 (HD) that I plan to do little to the body and alot to the powertrain to make it the salt bath long distance tow pig, and keep the 99 C3500 and 95 C2500 (HD) in good shape for clean weather driving. will be installing it with guages, but as a new idea, installing every factory piece, down to the shitty crossover and downpipe, and half-ass documenting temperatures, pressures, and speeds along the way. we never haul the same load twice, so it will never be scientific.
 
A GMC extended cab, long bed......Good platform to start with right there.

Any rust, Is the price right, Does the "Foundation" look to be in good shape?

What year is that rig?
 
This is the old e-Bay rig, she is allready bought and paid for. I bought her about 2 years ago for $2,325 with the description of high miles, but good body. Well the left rocker is dented up in, the LF tire blew at some point and trashed the inner fender, and there is slight surface rust apearing in the usual places. all in all, compared to some rust belt rigs, I guess she isnt in too bad of shape, but around here I rate it less than good. luckily, she started life down in texas, and only made it to northeastern KS, so still far away from the center of the rust belt, so the frame is great, nothing more than surface rust, is has had some preventative measures taken in the form of undercoating. so that is the good part. Hell, I amy love the ol gal enough I might find a clean 3 door cab to put on, and take her off salt duty someday! :)

oh, the motor was represented as good, but she had plenty of blowby at purchase, and it only got worse. a 2500K round trip pulling a loaded car trailer to california, it drank about a gallon of oil. about 6 months ago, it started idling on 7, now it runs on 7, idles on 6. so its a miracle she didnt blow on the road.


in the end, me and this truck have a love hate relationship, I hate that I was lied to, but I love the fuel economy and trouble free 20K miles I have goten so far out of it. in the end, if that is the worse screwing I get on a used truck, I am not doing half bad.
 
Did GM also skip I and J like AM general did? if so, my other 506 block must be a November 13th, 1998, as it is a M138.



Shifting gears, as far as bolt on durability enhancing parts is there any differences between a 506 and an optimizer?

If not, I am thinking the wise thing to do is go ahead and stud everything in the motor, and if she blows up, I can swap everything to an optimizer. I will probably throw a Fluidampr on, and maybe even a gear drive timing set.

Which brings me to the next question, directed at Leroy, what can you get from the above list? as far as your personal stuff you offer, I allready have your fittings I bought a year or two ago, and I might need a metrum rod fsu if I can afford it. Your oil cooler kit is still plenty happy on that very truck, and there hasnt been shavings in the oil, so I feel comfortable re-using the cooler kit.

thanks guys!
 
ok, so AM General and GM only skipped I both of them used J. So that makes my GM motor with the M138 a December 13th, 1998. Thanks!
 
I know this is way OT......But can you snap a pic of the last exhaust hanger closest to the tail pipe on one of the 3500HD's.

Seems one of my hangers was attached to the leaf spring and is screwing up the tracking.....Damn exhaust shop!!!!!!!!!!!!
 
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