So if I'm using the ford diffs or the JY dana 60 will the bolt pattern be the same as my 5 on 4.5 or do I put my axle shafts in the dana or ford diffs?
As Old Man Mopar said - most of the ford's use 5x4.5" (explorer/94+ Mustang), A dana 60 out of a junk yard will be out of a 3/4 or 1 ton truck, so you'll have to buy the car housing ends, and new axles
They're just options, that most of the time come with a good gear ratio, and limited slip. If you already have an 8 3/4 under the car leave it they are a good axle