eightbore, as a former engineering supervisor at Chrysler's Trenton Engine Plant (2.5 million sq. ft. machine shop) I agree with you. Also my method was a bit casual. By carefully checking from the outside of one hole to the inside of the other and then reverseing directions I get an average of 1.128. I believe this a good solid number and seems to indicate #2 frame. We had a tolerance of 3 light bands on water pump seals, try to measure that!
bill