Hey ya'll I have a 66 mustang and I found a 9" rear out of a junk 67 gt what is involved in the swap and should i rebuild the insides and if so with what? thanks i appreciate the help!

 

the ford 9 inch are great rear ends to have, ill assume the one you pulled it out of was a big block GT. If you want a more solid, reliable rear end, thats not to say the 8 inch isnt, the 9 inch was mainly used at ford, for their high horsepower cars, they used it for the larger ring and pinion gears. I have a guy in colorado that rebuilds old ford rear ends. he did the one in my car, and dont have a worry in the world with it. even if you dont want it in your car, fix it up, rebuild the gears, and sell it at a swap meet. Many hot rod guys loooove those rear ends so dress it up with 3.25's or 3.73 whatever your heart desires.

 

The 65-66 9 inchers had an axle length of 57.25 inches , whereas the 67-70 9 inchers had an axle length of 59.25 inches. So, do some careful measuring to make sure you still have enough room to put your tires back on without rubbing. I wouldn't think that one inch on each side would be that big of a concern, it just depends on what wheel and tires you plan on running. It also depends on what kind of driving you are going to do in regards to the gears. If short sprint racing is your cup of tea, then up to 4.30's can be added. But, if it is mainly for street driving, then anywhere from 350's to 373's would be under consideration. If you don't plan on racing, then the old 8" is a tough rear, and will still handle a bunch of HP.