I decimated my rear end

The new engine isn't even broken in yet, barely 250 miles, I have never even pushed it passed 5000-5200 rpm yet,and I was just leaving a stopligt on santa teresa here in san jose and I heard a snap-ting! sound, and I drove it back home, it was a loud sound, very loud, I heard it twice more and the worst one was pulling into my driveway, as I barely eased it into the garage it SNAP-TING!ed again and that was it. I raised the back end off the ground, put it on some jack stands, put it in neutral and spun the back wheels, the driveshaft doesn't turn, only catches a little with a thunk then settles back, I called rear end specialties and the only thing they have is a rebuilt lincoln versaille 9" for 2000 dollars, hahahaha, not funny, I got like 325. So, I'm locked down for now. I must have done something right with the engine, it's making alot of torque, I guess, enough to bust this cheesy little 7 1/4 rear end. Crap! Aint even broke in yet, I'm so mad! Not a happy moment.