2007 classic GMT800 with "M" code in the VIN

[Full Lock]

i traded my 2014 couple months back and now I'm looking for something cheap to daily.

Anyway I found a 2007 classic GMT800 and the guy gave me the VIN and the 8th digit is "M". That is the 5.3 VIN code for the GMT900 NNBS trucks. Has anyone come across this situation or did GM Put the 315hp aluminum block in the classics and change the "B" code to a "M" code for the mid model year change over?

Another strange thing is the VIN came up as a crew cab when the truck is actually a extended cab.

 

First time I've seen any of this.

 

Any input is appreciated!

[MS3DALE]

Not sure,but....if you give me the last 8 of the VIN I can run it on the GM side and see what it says,something doesn't sound right.

[Full Lock]

I'll PM you with it, thanks man