Those were the years I was looking at too, as I read about how the earlier 2.7L engines weren't as good. How different are the Turbo cars from the "regular" 911s though? Would it work like an old Mopar where you can buy a base model and easily swap in a built-up engine and upgrade the suspension and brakes, or would it be more cost-effective to just buy a Turbo car from the start?