Having a straight rear end housing is very important to the overall handing of your race car. Just as you carefully align your front end so the wheels are pointing in the right direction, the same needs to be done with the rear housing. I would venture to bet that most race cars have a bent rear end housing. The reason for this is most people have no way of accurately checking. When purchasing a new rear end racers naturaly assume that it is straight.  Think again!  Even if straight when purchased, it will probably bend when you weld or tack weld the brackets to it.