I was running a rear 70HD on my pulling truck. At my last pull, right before the 300' mark, I ended up twisting off the pinion gear right at the end of the yoke. I'm planning to upgrade and thinking about a Dana 80. I've located an 80 out of an E350 with 35 spline 1.5" diameter axle shafts. Are any of you guys breaking gears or shafts on the Dana 80's with 35 spline (1.5" shafts) or 37 spline (1.6" shafts)? Is anyone running upgraded / aftermarket shafts in their 80? -thanks-