Diff measurements

[snapper]

Don't forget the wheels and tyres, the rolling radius will also effect your gearing.
There are a number of gear ratio calculators, I used them for my initial build.
Diff ratios you are likely to find will be from the Sierra, 3.9, 3.6, 3.38 and 3.14 you can then fine tune with wheel size and tyre profile.
From my experience by this time either your wallet will collapse or your head will explode