With no intention to rain on Tom's parade here, you might want to look into the Ford Aluminum 8.8 IRS center from an 03/04 Cobra or an '06 - '10 Ford Explorer as an alternative to a 9" Ford. Below is a link to a post I did a while back sharing some information on that particular solution. While not as strong as a 9" they still easily handle 900+ hp in 3400 lb SVT Cobra's. Click here =>
Ford 8.8 IRS
There is also a very nice HD rear cover available for them from right from FRPP, click here =>
Ford Racing IRS Cobra Axle Girdle
When you get done with the conversion the 8.8 IRS center and associated toys will be less expensive than the 9" option. and very likely more than adequate for the application.
Ed