1967 Rear End

Welcome!

You should post these questions in the classic forum. There are knowledgeable people there that should be able to help you out.

Sent from my Nexus 6 using Tapatalk

That short question has some long answers, I wont go into details but hopefully I can help you narrow down your choices.

There are three relatively easy to install rear ends that are worth having/doing...the 8-inch, the 9-inch and the 8.8.

They all have advantages..
the 8 is cheap. lightweight, low drag. and a simple bolt-in
the 9 is seriously strong, with a penalty in parasitic loss and weight
the 8.8 is the hardest to install since it was not offered back int he day, but it is a nice compromise on the above two and can be found with factory disc brakes.

I would not go the 8.8 route unless you can do the fabrication yourself or are willing to pay a professional.

There's also a long thread that has been stickied, you can find it here:
http://www.stangnet.com/mustang-forums/threads/rearend-swap-info-faq.656567/