2. Currie has two different F9 housings. Both are similarly braced inside. This is the base model with a 3⁄8-inch-thick face. You can also see here where the tube gets welded to the inside of the housing at that circular opening. The high-zoot housing is intended for trophy trucks and is physically bigger and accepts larger-diameter axletubes. Since were already concerned about space under our Jeep and we are going to be going much slower than that, this smaller housing should be plenty for our application.