I have a project of drilling three 2.00" holes in 4 X 5 rectangular tubing . The tubes are 99 inches long the holes are 47.5 inches apart. Tolerance are .010 on location. I have 60 inches of travel so two set ups are a must. I could have up to 2 thousand to do. I am looking for ideas on a quick & solid work holding fixture . This is a horizontal mill with two large angle plates. I am leaning toward two air vises. I don't know if they will hold with no part movement. Any input to this would be appreciated.

Thanks daveb56