Connecting Rod Bearing Selection: Notes

Each connecting rod falls into one of four tolerance ranges (from 0 to 0.024 mm (0.00094 in), in 0.006 mm (0.00024 in) increments) depending on the size of its big end bore.

It is then stamped with a number or bar (1, 2, 3, or 4/I, II, III, or Nil) indicating the range. You may find any combination of 1, 2, 3, or 4/I, II, III, or Nil in any engine.