hate to say it, but without the actual VIN# or previous owner info, you will never track it down and you are shooting in the dark. they made almost 12,000 Barracuda's in '74, of those @ 5000 were designated special 'Cuda models. how many are around 40 years later? it could have gone anywhere - different state, different country, someones garage or barn, someones scrap heap, made into a parts car, restored to new, who knows. you need #s to research it.
any old paperwork he left around (registrations? insurance?) that might have the VIN# on it? maybe you can do a title search in your state based on his name (there are companies you can pay to do this too if it's that important to you)? a pic of the license plate might help you back track it through the DMV?
don't want to discourage you for sure, but you need more data (#s) to get you going in the right direction. I wish you the best of luck.
I was lucky enough that my dad parked his in the back 40 @ '87 and forgot about it
