You first need a 1970-1973 radio bezel. Does the car have a radio bezel right now? The radio doesn't mount "in the dash". It mounts to the radio bezel, then the radio bezel mounts under the dash.
There is a bezel on the stock 75-77 radio and it looks like the mounting holes and tabs on the top of the bezel in the pics are the same as the holes in the top of my radio opening. Are the 71 bezels different from the 75-77? Thanks
They might mount the same, but I don't think the 1973-1977 radio bezel would look right in a 1970-1973 car. They are totally different.