550-600HP 4spd suspension help

my friend has a 408 stroker in the 500/500 range with a 4 speed and the car hooks well and the weakest link is the axels he launches at 3600 and all is well .he wanted to inprove his 60ft so he did a 4000 launch twisted the axel off every time with drag radials the stiff side walls dont asorb shook like a slick .a soft wall slick will help with breakage .