I have a set of motor mount frame brackets that I bought from GM years ago. One has part #3980941 stamped in it and it measures 1 7/8" to the center line of the mount bolt when laid flat on the bench. The other one is not stamped clearly so I can not read the part # it measures 1 3/8" to the bolt center when flat on the bench. I bought these as a pair and was wondering if anyone could verify these measurements.