I had an '84 SVO and found it to be a very well put together car for 1984. Hot Rod Garage did a 2.3 Turbo Coupe build utilizing the stock motor and upgraded turbo/header/cam and injectors that made EcoBoost horsepower levels. Personally, I'd go that route and keep it "original"'ish. Pete Kotzur (San Antonio machine shop legend) had one that ran in the 12's back in the mid-90's.