: N* Serial number

04-10-07, 04:53 PM
Hey guys, sorry if this has been covered in a previous thread, but where in the hell is the serial # on a N* motor? Must be buried under somethin. Reason I ask is I have a motor that I think was out of a 95-96 Eldorado and want to research it further. Once I have the number is there a way to decode it? Is it a 275 or 300 hp version? Then how would I trace it to the vin of the original car? I want to run a carfax on that car and find out if any smoke was blown up my skirt about this engine. Thanks for any help.


08-03-09, 03:43 PM
under rear cylinder bank (or right cylinder bank if you are oriented the same way the engine is).
behind Rear headers and Transmission

08-03-09, 06:26 PM
The Northstar has a machined pad on the block, just under the right (rear) cylinder head at the "front" of the block, right around the corner from the serpentine belt. The engraved/stamped number on that pad is a "VIN derivative" of the original car number. A GM dealer should be able to decipher the meaning. MAYBE there's still a sticker on the front of the right (rear) cam cover. A CARFAX will tell you basic registration changes and maybe emissions tests - because that's a voluntary reporting database, there's not a lot of info on most cars. IF a dealer can find the whole VIN, ask them to run a GM VIS check - all GM warranty, recall, some service work on that car.

Mark C
08-04-09, 10:11 AM
The one on my 98 motor I bought had LD37 and the last 8 characters (which is the year built, assembly plant, and the 6 digits of the sequential build number) of the cars VIN under the LD37 engraved into the pad. The pad is on the rear of the block next to cylinder 1 just above the oil pan flange as described above, its about 2" long by 1/2" tall. Looked like the numbers were done with an engraving tool instead of a stamp like they used to do in the past. Must have some kind of automatic engraver on the assembly line that does it in one quick pass.