I have a N case with a 31 spline / axles ,locker but with factory 3.89 gears. I love the ratio but how strong are factory gears? Its a lite car 3000 lbs with 600HP and a 4 speed.

There are 2 versions of the nodular case, one with nodular caps and the other with grey iron caps. If yours has the 3 1/16 bearings then it is the stronger one. If it has the 2 7/8 bearings then it is the weaker one. Do you have the Detroit Locker or the Traction Lok? The locker is probably strong enough to handle your combination, but the Traction Lok is not. There are also 2 different stock pinion housings, the standard and the Daytona housing. The standard housing has the same bearing on both sides, but the Daytona has a much larger inner bearing. The Daytona is the one you need to use, or go to an after market aluminum pinion housing. The ring & pinion gears are as strong as any aftermarket street gears, as long as they are in good condition and set up properly.

Its the large bearing N case with a real "locker" ( not a traction lock)I dont have the larger pinon bearing support though ( daytona). I want to change my axles out soon so Ill go with the daytona support while I have it apart.

When you get the Daytona pinion housing be sure you get the yoke to go with it. A standard yoke will not work with the Daytona housing. Your nodular case should have had a Daytona in it. Did someone remove it before you got it?

Please excuse my ignorance !

I set up the rear about 4 years ago.To be honest now that I think about it there was a large and small bearing in the support. Hey Im new to this !!
This was my first 9" and I was still learning. It came out of my old 70 Torino with a 429 / speed combo ( got totaled parked in front of my house) I pulled it down and replaced everything ( bearings, seals etc) and replaced the traction lock with a Detroit locker. The only only parts I reused were the gears. They looked great and the pattern turned out very nice. I was just wondering if I made a mistake in not replacing the gears. I think I'll leave it the way it is.

Sounds like a good idea. graemlins/thumbsup.gif