8 3/4 What will it take ?

Buddy of mine has broken 3 of them in the last 2 years in his 500 hp 408 duster with a 4 speed. Breaks the pinion clean off w 489 or 742 units. I keep telling him to go w a dana 60. Especially if he plans to keep side stepping the clutch @ 3200 with M/T drag radials. I'm sure he would be fine with an auto.