Back at the track with TCI 10 inch

[flathead52]

We my son got to run today, Had no luck hooking the car, till he hit second gear. Times looked like this 8.70 with a 2.11 60ft time at 92.65mph this was in the 1/8. On his third pass of the day when he came off the gas at the big end he dropped the driveshaft. It snapped the ear off the shaft at the rear end. What is anyone using thats holding up?