Brand New 7290 U-Joint Failure

Well on the street I guess no more power shifting but I think the combination of big tires and the 3:23s with a strap type hold down may have been more than it could take. I havent seen the pinion yoke yet. The drive shaft was built locally without any grease fittings. Had less than 1000 miles. Anyone know anything about Dennys Drive Shafts. Everything going back will be new as well as the 489 case with 3:91s. Dennys has a driveshaft for $450 that will handle up to 700hp, way more than I am making. Uses 1330 joints and 3" tubing.