[UB DRMNG]

I like your paint ideas, My F5R is silver with dark blue stripes.

The 9" is a great, very strong rear end but I think it is overkill for the really light weight of the Cobra/replicas. You might be asking for trouble with that much unsprung weight with a 2,000 lb car. Plus with a complete kit you would have to modify the kit parts to work with the larger axle and probably need to have the axle shortened to keep the wheels under the body. I am not an engineer but have used both rear ends and I think the 8.8 is the best choice for the Cobra replica. If I get to build a Cobra I really want to put in an IRS. Even less unsprung weight... better more responsive ride!

The F5R and I believe most other kits are set up for the Ford 8.8" rear end like used in the Mustang in both the straight axle and IRS pumpkin (if I am not mistaken)

Building a car is a great, sometimes frustrating experience, do your homework and get what you think will fit your needs the best, then have fun!