Cut pork tenderloin in half lengthwise (if it is thicker than 2 inches, cut into thirds lengthwise). Sprinkle salt and pepper over pork. Mist a ridged grill pan or skillet with nonstick cooking spray and warm over medium-high heat. Cook pork, turning as needed, until no longer pink in center, 11 to 13 minutes. Remove to a plate, tent with foil and let stand.
In a bowl, stir together lime juice, sugar, 1 tsp. black pepper and 1/2 tsp. salt until sugar is dissolved. In a large pot of boiling water, cook noodles until tender, 2 to 4 minutes (or according to package directions). Drain, rinse until cool and drain again. Place noodles in a large serving bowl and toss with 3/4 of lime-juice mixture. Gently mix in lettuce, carrots, mint and basil.
Thinly slice pork and place in a bowl. Toss with remaining lime-juice mixture. Top noodle salad with pork slices and any reserved juices and serve.