Shown here is the main difference between the '69 and '70 regulators. The arm on the '70 regulator on the right is straight, while the '69 version has a small bend in the arm that attaches to the front plate. Although it's a close call, the need for new regulators should be determined on a car-by-car basis because if a car's existing '69 regulators are in good condition they might work with the '70 glass and plates. You can attach the assembled glass and plates and an existing regulator in the door fairly easily to determine if your existing regulators will work. If there isn't enough clearance in the door for the arms to work on the '69 regulators, installing the '70 regulators by themselves is straightforward. Ours were worn out, so we replaced them with the new Scott Drake units.