Go with the 741. Remember that the gears only transmit the torque the rear wheels can resist.

So if you are running slicks and have done chassis work so your car hooks well, you need a Dana 60. But if you're running street tires and a nearly stock suspension that 741 will live forever. Plus remember that automatic transmissions can't shock the gears like a stick.

Plus running 4+ gears on the street is a pain unless you're really into hearing engine noise.

R.