Does200, yes my GT5-S is slightly modified because it doesn't have the original 351C engine, nor does it have the original wheels. The 351C engine is a very common inexpensive motor. As you know the Fontana engine or Clevor motor is much lighter and a merging of the best parts of the Cleveland and Windsor motor. I think in most peoples eyes the Fontana engine is a nice upgrade over the original motor while still having the period look from the '80's.
When I bought this car it already had the Fontana engine so I don't know who built the motor. Although this motor did have a racing cam with solid lifters. Malin Motors swapped that out with a mild cam with hydraulic lifters to make the car more streetable.
The original 15" wheels and tires are useful if you want the car to be a museum piece on display but not very practical otherwise. The 18" wheels are much more practical in this day and age. Of course the purest can still get the original wheels for this car from Marvic Wheels in Italy.
As for the ridiculous smog rules in California, I haven't had any issues. My car has California registration and I drive my car no problem.