I owned a 1973 impala 2door. as I remember the caprice had more options and was more money. I paid 4,200 dollars for it and the only problem I had was the distributor points always changed dwell, and of course the timing.13 miles per gallon a real gas hog. My 1967 442 got 18mpg. and twice the h.p.
I have had several Impala's from the 60's and I currently have a 66 Impala. The Caprice is a step up from the Impala with more options included from the factory. The bodies are the same with the exception of some trim pieces such as the tail lights.