Pictures of 72 Blazer & 72 Jimmy both from St. Louis.

[Big Block]

Does anyone know if Blazers and Jimmys came off the same assembly line or were there two different lines, one for Chevy and one GMC? Both are 72's and are from St. Louis. Blazer vin CKE182S16XXXX and Jimmy vin TKE182S50XXXX. From the numbers I'm guessing that the Blazer is earlier than Jimmy. Does anyone have an ideal when they were built. The truck is a 70 but from the vin it looks like it's a 71! What's up with that? Vin CS1341Z5XXXX. Looks to have been built in (Z) Fremomt Ca. Shouldn't the one before the Z be a 0 for 1970? Help please!