[Paul Ceasrine]

In 1968,,,,,,,,
The 383 Road Runner was only available with a 3.55 gear ratio
(Performance Axle Option).

As listed per the sales order form.

The 3.91 gear ratio could be ordered, as a
'Special Order Option Only' which was not on the sales order form.

The salesman had to know the 'special code' to get the car to come
through with that option.
Any cars delivered to the dealerships back in 1968 (regular dealer stock cars), either had 3.23's or 3.55's only.

That is why all 68' 383 Road Runners tested by the car magazine auto editors
were either 3.23 or 3.55 gear ratio's. Only standard or regular optioned cars were tested.
pc