I'd imagine it would be a near enough bolt in affair, but youd be better of getting something made to fit by a local fabricator than an off the shelf cage.
The cage I had built for my car was under half of the cost of an ATI bolt in, and it was built around my seat and driving position to make it as safe as possible. Depending on what cage you'll likely be a LOT safer too, for example the cusco (AKA crashco) are notorious for collapsing in the bends around the dash and thats the last thing you want.