I have a 68 Charger that I'm putting a built 360 in and found two different chunks for the same price they are both posi units one is a 741 with 3.91 gears that has never been run and the other is a 489 with 4.56 gears the car will mainly be street driven and track every once in a while. I'm on a tight budget since my wife lost her job and don't have extra money for gears for the 489 because 3.91 was the gear ratio that I was looking for. The transmission is being beefed up with high performance parts and has a 3000 stall torque converter. I have 17x9.5 rims with 265/40/17 Nitto's 555 just wondering how the 741 will hold up I tend to have a heavy foot.

As long as the rear end is setup right, by that I mean, backlash, pinion depth, bearing preload and angles you shouldn't have any problems.

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.

vote for the 3.91 gears

Thanks for your input guys.