OH-58 had requirments to the military spec,
the Bell 206 had CAR 3.
The airframe on the OH has the battery in behind the fuel tank (No nose door) fuselage has different stations & construction .Doors jetison,Armor backed seats,Hard points for guns, T-63-700 allison power (C-18) needed larger blades for disk loading requirments, So many little things are not the same, Mission equipment all over-Flew both-Worked on both.
Both are nice machines.