What's the fastest diesel motor and transmission that I could fit in my 1980 Volkswagen Rabbit?

I have a 1980 Volkswagen Rabbit that has a 1.6L Diesel motor but im looking for something eith more horsepower. I want a diesel motor that will fit in the car but doesnt require a lot of work (or major changes). Can anyone help me out?|||There is a turbo upgrade kit that u can added to squeeze more hp out of it. Its mostly bolt on too.