Main new parts compared to T3-11:
301132 T3-12 chassis
303087 T3-12 shock tower rear
302086 T3-12 shock tower front
301193 T3-12 upper deck
302526 Composite dual servo saver arm
372503 Composite servo saver X-stiff
302253 Composite steering block hard
along with gear diff, upper clamps, open ball joints and pivot balls, and of course different turnbuckles for the servo link.