rear end

i jus got a brand new torsen posi unit for 100 bucks and i have the stock rear end set up with about 400 hp, is there a possibility that i could rip the rear end out of the car, ive never done rear ends before and this is my first camaro, there is a bar that hooks to the chasis to the rear axle ive already ripped that chasis, should i wait and strengthin the rear end before i put the posi unit in it