If the length fitting result gives the change of more than 1 inch (2,5 cm) it makes significant difference in swingweight and Moment of Inertia (MOI). This effect could be partially compensated by adjusting lie angle.
The well-known rule of thumb is that ½” of length trades with 1 degree of lie. But it is the general estimation only and exact values depend on the club length.
The calculator below indicates more precisely the recommended length change after applying the lie correction.
update: May 2020