[57taskforce]

Driver side top of the frame rail should have a partial vin number stamped right under the cab as well as the top of the frame by the steering box if it’s a 72 frame. Earlier trucks especially GMC are known to not have vins by the steering box. Not sure if the earlier trucks had the stamp under the cab or not. My 72 K20 did. You will have to lift the cab to see the vin under it. But the other by the steering box is pretty easily seen if the frame is clean.