I`m building a 400hp 383 which most of you know by now Thanx to the people who helped me so far

well for my ? I want a rear end that will hold the 383`s power I`m thinking 12 bolt but I can`t think of any that will fit in my 3rd gen because of the torque arm so will a 9 bolt be strong enough or a 4th gen 10 bolt or is there any 12 bolts that will fit? and no I`m not useing a 9 inch that`s a ford piece

 

With a stick, I'd go with a Ford 9 in

 

I would keep the ten bolt. You can hold up to 500 horse on it . If you have a girdle, and auburn gears. Eaton posi unit also. I am looking into it , and Drive Train Specialists by me said it would hold no problem. Just cheaper man its up to you a narrowed for nine is expensive

 

I agree, with 500hp or less the stocker will hold up, a girdle is a good way to keep the bearing caps from flexing, and after maket gears are stronger, and a beefed up posi is a MUST. Nothing like having chunks of your spider gears lock up your rear end under high acceleration.

 

The best thing to do is to run your stock rear with a girdle and hope it holds up. No direspect meant to the others that posted but a stock 10 bolt will not be a reliable option for anything putting out in the 400 horse range. I know that there are people running that kind of power with a stock rear, but those rears fall in to the same freaky catagory as the T-5's that shouldn't be surviving but do. Once the stock rear goes, make the step up to an aftermarket 8.5" 10 bolt, 12 bolt, or nine inch. It is one of those things that you have to use fore-site on, do you want to spend 800 bucks beefing up an anemic rear only to have to replace it in the end? I personally am running a moddified 8.5 inch 10 bolt that utilizes all the stock mounting points including the torque arm, and I should hit nines this year on a full weight street car. Whatever route you take, take the advice of anyone who has been building the same car for a few years, and minimize the amount of money you have to spend twice on the same component.