Join Date: Jan 2018
Location: Coopersville, MI
No 10 bolt, 12 bolt, or Ford 9" is a direct bolt in unless it has already been modified or is ordered from a company as a direct bolt in. With that said it would help to know why you need a posi-traction rear end? If it is for drag racing and such then yes you need a different rear end. If it is just a want and you are running a fairly standard HP engine in the car then you may just want to look to retrofit your existing rear end into a Posi. Drag racing then I would stay away from the ten bolt. The next question is how much torque and horse power are you going to put into the rear and what kind of transmission are you going to run? If your going over 800 hp then a standard is out of the question unless you go with a Lenko, but if your not doing something as far as tubbing to getting bigger meats on the rear you will never get 800 hp+ to hook with a tire that fits in a standard wheel well. A car 12 bolt and a ford 9" are about the same in strength with a little going to the ford 9", but also the ford 9" steals more power from the wheels due to the location the pinion gear rides on the ring gear. Ford 9" makes gear changes easier and comes standard with bolt in axles, but is slightly more expensive than a good car 12 bolt. 12 bolts can be built with bolt in axles and up to a 35 spline axle. The aftermarket though is flush with Ford 9" upgraded housings that can handle insane amounts of torque and horsepower.
The one rear end that seems to get over looked a lot is the Dana rear end. The housing is heavier, but in a stock housing it has the largest ring gear. They are only slightly more expensive than a 12 bolt to build and can handle brutal amounts of torque and horse power in a stock housing. I'm currently building a Pro Street 63 and am tossed between a 12 bolt and a Dana. Right now I'm only looking for HP numbers around 800 - 1000 which a built 12 bolt can handle, but if I get the bug for going faster the Dana would let me put more torque and horse power to the ground before breaking.
1963 Impala Convertible (Frame off resto-mod in progress)
1963 Impala 2 door hardtop (Pro Street build in progress)
1963 Impala 4 door hardtop (Parts car)