Hole saw with a right angle drill was used for the inside frame rail on passenger side. All the holes were done with the jigs tacked in place. I used 1.75" hole saw just cause it was the closest one i had size wise. Im not home to measure at moment, i believe 1.875" is the correct one. All 4 holes i went over with right angle die grinder to clean up the torch slag and just fine tune them to match the jigs.