Referring to an A-body Barracuda, as a 'Cuda, is 100% correct. Why? Because that is PERIOD CORRECT slang for that car.
"Oh my '65 'Cuda isn't a real 'Cuda like your '70 is? Well I'll have you know my 'Cuda was roasting tires on the street and getting it's windows fogged up every Saturday night, long before your 'Cuda was even sketched on paper!".
The A-body 'Cudas set the standard and have every right to be called a 'Cuda. MOPAR just capitalized on it, very successfully I might add.