I would guess there are a large number of Mustangs with 4R70Ws that have been JModed.
If it is a post 1997 one or 2000 or newer than most of the information here isn't as relevent as it is for us, you need to find an updated one (since other than the 98 Mark VIII 97 was the last year for these cars). There is a document floating around on crownvic.net for 2000+ cars.
All the sizes listed for all levels and holes are commonly available bits, you don't need to convert them to fractional, you can get them in the decimal/numbered size. Obviously some of the exact decimal ones (0.125- 1/8) you would get 1/8, but the numbered ones like 20 and 3 you can get singly or in a big ol box o'bits. I found them all at Graingers, and almost ordered them when I went to my moms shop and they had this 3 feet tall by 20 feet wide wooden/glass display of thousands of bits, multiples per fractional/decimal/numbered sizes and just got them from her. I have the bag of them next to me now!
97 Mark VIII LSC/Silver/Gray leather
97 Cougar 4.6 Sport/White Opalescent Tricoat Metallic /Gray leather down but not out?
89 Cougar LS 3.8/Oxford White/Gray velour/HG need replaced AGAIN
00 Grand Marquis LS/Vibrant White/Gray velour
63 Falcon 302/black and rust/shed isn't moving
82 F-150/Oxford White/dumb VV carb doesn't pass emissions