When searching for that info I find that they made a sedan and a sport sedan . I am guessing that the sport sedan is the hardtop. Just to be sure can you verify the model number ? Should be either 1BN69 or 1BN39. 

Hello Omid, you were wondering how many Caprice Sport Sedans were built. I looked m

in my 75 Years of Chevrolet Book for this information. According to this book there were 40,482 Caprice Sport Sedans built in 1975. I hope this helps you out in your search for this information. These Caprices were very nice cars to drive and ride in. Back in 1976, I was able to drive a similar 1976 Impala Custom Coupe when it was new, and was amazed by the performance, ride and quietness of this Impala. Some people criticize this car because of its size, but to me if you enjoy a certain car, just enjoy it for what it is. .... John