Quote: Two different worlds, drag racing and 4x4 trucks. Dead hooking a 1500hp car is a lot harder on parts then a 4x4 spining off road where traction is a minumin. If you think a dana 70 is only 15-30 more pounds then a chromoly housing, aluminum center section 9 inch your crazy.
Tell that to the jeep guys that have serious traction in the rocks, they slide a little back, wheel is under load and then catches...Many v8 powered jeeps have either broke something like a shaft or a housing or launched the vehicle over backwards. It aint muddin I am talkin about here... oh and the 70 with 40 spline axles are good up to 8000 ftlbs of momentary torque, the 60 is good for 6000 lbft of momentary torque with 35 spline. I don't see any 9 with factory parts rated to even close to those numbers the 8.8 with 31 splines is about 5100, the 9 is 5500 per one chart on the web. So you can decide what you want....just barely makin it or never going to break. I went with a 70, it was like 6 lbs heavier than an HD 60, I don't think I will ever break it under normal circumstances. Tim
Last time I checked a prepped smooth racing surface has way more grip then any rocks I found off road. Haven't seen any 1500 hp rock crawlers either. If you want a Dana 70 and all that weight in the car that's fine, as for me I want to go fast.
You do know Montes 9 inch is behind 700+ cubic inch nitrous breathing monster and lives fine, but I guess that's not the same as some rock buggy with a ls 6.0 liter in it. Do me a favor and put your car, when your done building it, on a scale and tell me what it weights. Also why do we need to put factory parts in these rears the aftermarket is full of awesome super strong parts for a 9 inch. I am building a race car not a confined to factory parts.
Brett Miller W9 cnc'd heads STR Chassis fabraction
oh and the 70 with 40 spline axles are good up to 8000 ftlbs of momentary torque, the 60 is good for 6000 lbft of momentary torque with 35 spline. I don't see any 9 with factory parts rated to even close to those numbers the 8.8 with 31 splines is about 5100, the 9 is 5500 per one chart on the web. So you can decide what you want....just barely makin it or never going to break. I went with a 70, it was like 6 lbs heavier than an HD 60, I don't think I will ever break it under normal circumstances. Tim 
