I called the maker of the cover. thet said the 1966 Cuda is made same height and widt. But is made 183.00" long and the Duster is 187.5 but had some extra flannel, left over, heavier than they normally use. From a special order. So made up some in a few lengths with no mirror pockets. AS SEMI CUSTOMS. And would send one at 100 bucks.
