1967 Mustang Rear End

Any 67 -70 8 inch or 9 inch will bolt in .I believe an explorer rear end has to be modified to work .The front spindles are all the same 67 to 69 and 70 spindles are actually better but have a larger outer bearing .so a drum change to 5 lug is easy or you can go with kelsey Hays 65 -67 disk brakes and they bolt right on .

Unless its new that is pretty high for a used rearend .you should be able to find one for around a couple of hundred .
You would need to find out what gears are in it also ,it will probably be around 2.70s and that would be way to high . 3.0 or 3.25 would be a good ratio .there is a tag on the third member ,the 2 or the 3 is sometimes hard to see because it is right at the edge of the bolt but if you can easily read .70 it will be to high .25 would probably be 3.25s