I decided on the motor and trans i want to rebuild thanks to this site. Now i need help in deciding on the rear end can the stock one be built to handle around 450rwhp or should i go 9 or 12 bolt moser or if there are any more ideas,It will be very helpful.

 

Depends on what tranny you have (A4's are easier on the rear), what kind of tires you use (slicks cause problems) and how you drive it. Treat an M6 with a little care and the stock rear will last. Try a few 6K clutch dumps with slicks, and you can kiss your rear goodbye.....

I personally prefer the 12-bolt to the Ford 9-inch. The 12-bolt is lighter, has a 3% better mechanical efficiency (less drive train HP losses), and "fits" better. The primary advantages of the 9-inch are that it is relatively easy to have a spare center section with a different gear ratio, and swap it out in an hour, and the ultimate strength is probably higher. Base model 12-bolt against base model 9-inch will probably not see any major strength difference. The Strange and Moser 12-bolts have been demonstrated to handle upwards of 900flywheelHP.