Rear Gears.....

Can someone tell me what rearend will fit a 1974 Grand Prix with at leat a minimum of 3.73 gears? Or does someone make these to bolt into the existing differential. I need the rearend to be able to stand up to about 425 HP w/441 ft/lbs of torque.

Thanks in advance for any assistance.

Companies such as Currie and Moser will build a rear end to your specs. Is the rear end in the car now a 12 bolt? If it is, there are many companies out there building gears for 12 bolts. May want to check with Richmond Gear, just the first name that comes to mind.