Hi folks, I was hoping some one might be able to help me ID my motor. I picked up an '80 GMC Sierra 15 stepside to restore and it has a 6 cyl. eng. that is done. I got it running but just barely. So I have to replace/rebuild the motor and it's decision making time. The easiest thing to do might be to replace with a salvaged motor so I can keep it running while I'm restoring because changing out to a V8 means the entire drive line which is more than I can handle financially. Soooo, all things considered, how do I tell if I have a 250 ci or the 292 6 cyl.? I haven't been able to find the method to decode the vin yet, or whatever describes the make up of this vehicle.