How to tell if you have #s matching on GM?

[41husk]

Nieghbor came over and is looking at a 65 Chevelle and wants to know how to tell if it is #s matching.  Engine #GM3858180 VIN# 1336375G104429.  If any GM guys can help, Thanks!

[hemi-hampton]

Depending on year they start or end with 2 letters then #'s some start or end with 3 letters then #'s. For example you'll see alot of older 60's Camaro Z-28's refer to a Engine ID# like DZ or MO.  These decifer to a Z-28. Finding these 2  letters & looking them up will will tell you what year & car it came from. Vin will tell you the rest. On small block Chevy's this # should be on a small milled pad on block in front right where the drivers side head meets the block if I remember right but I'm rusty on my Chevy info. I had some more of this info somewhere but have not seen it in years. LEON.

[Ghoste]

From what I've been told, the GM cars are probably the easiest musclecars to fake anyway so numbers matching becomes a bigger coin toss as far as being legit.

[1969chargerrtse]

I'm rusty on this , my old Camaro pace car was 124679N619395 and that's from memory.  I knew what all those numbers met at one time.
1 was for Chevrolet, 2 for Camaro,4 was v8, 67 was conv,9 was 1969,N, was Norwood Ohio.and all Camaro's started at 500,000 so it was #119395.
This should give you an idea but just Google the info.

I would look at the firewall tag which had the production date. A13 being like Jan 13th.
I would then match the block number date and go as far as the block cast date.  You need the cast date to be before the motor stamp date.  You need the motor date to be a little before the body built date on the firewall tag.
You also want to check the block infor I.D that it's is for the Chevelle.  That info should be for the 65 Chevelle, and dated around the time the firewall tag is dated.




It's been decades for me so I hope this info is 100% correct.

I would look around for cast dates of the block, heads, manifolds etc... to get an idea if the year is correct?

You sure the VIN is correct?  When I went to a decode site it says the vin is wrong?

http://www.decodethis.com/PatternDetail.aspx?id=47

[mauve66]

#'s matching comes down to this.........

does the front license plate match the rear license plate??  then its #'s matching