I wouldn't consider anything BUT a fabricated housing in a serious effort deal.....especially a heavy drag radial car.

Racecars are hard enough on parts as it is, so why the heck would anyone roll the dice and in the end, have to spend twice (at least) when the compromised part is on borrowed time from day one???

It always costs more in the long run and sometimes hurts more than just the affected part, like in the case (no pun) of a severe transmission explosion.

When it comes to rears and transmission, there are so many good choices in aftermarket race "style" solutions.....at reasonable cost, it doesn't pay either in money, or safety to play games.