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GMC 270 casting numbers.

Posted: Thu Apr 20, 2006 3:09 pm
by Matt
Just to follow up on the thread under parts for sale I would be interested to know if anyone has details of 270 block casting numbers. looking at the block in my truck(engine number 270 53039) there are several numbers on the left(drivers) side,these are GMC 2135412 and just above 4 12 which is actually cast upside down.these numbers are quite hard to see due to the exhaust pipe,but unless anyone has a list of casting numbers I thought it would interesting if others could see what markings are in this location on their 270's.

I know I have asked this question before,but does anyone know if the 4 12 indicates that the block was cast on the 12th of April??

Thanks,

Matt.

Those numbers

Posted: Fri May 12, 2006 11:58 am
by Karoshi
Well it took a little time, but here's what I got. The casting numbers so conveniently hidden away that even a skilled circus contortionist would have difficulty read;

GMC 3. 2135412. then upside down: 02 35

I intended to post a picture but MyPicGallery is not being co-operative!


Do these numbers tell you anything?

Posted: Fri May 12, 2006 1:10 pm
by armydriver
These casting numbers may be more of information to the foundry than to GM or us. Generally they are mold numbers and as the foundry had many molds of the same configuration, if they ended up with a series of bad castings, the mold number would guide them to the culprit , the mold, that would have to be fixed or replaced. Just my opinion though. That is the way it was in other cast items I have dealt with.

Posted: Wed May 17, 2006 9:14 am
by snow man
I took a pic of ser:#s on my block { drivers side } seams to be the same except for the ones up side down . Image