28 to 31 spline axles

[furray]

Can you put 31 spline axles in a housing that had 28 or is the wheel brearing flange different between the two ?

[JTS71 Mach1]

I don't believe there is any difference in the housing itself. The side gears in the differential would definetly have to be changed, or the whole chunk as it was reffered to. Other then that I believe everything is the same. Anyone else know more??? JTS 71 Mach1[/b]

[1969jimmach]

You are correct you can put 31 spline axles in the housing only the center section has to be changed as well the carrier is different where the axles enter it so to speak.I have bored them out and changed the side gears and clutches before.But way easier if you are changing gears to swap out whole 3rd member too.

[furray]

I was thinking the wheel bearings outside diameter might be different ?

[gxr02190]

No difference in bearing diameter.

[ylwhrse]

I am about to change my buddy's 3rd member (chunk) as its called and axles and gears. I already have a lightened Detroit locker with 31 splined side gears that was an extra buy for me for an extra and an aluminum center section with the through bolts for added strength and it takes the "B" series size bearings which I believe is 3.06" cant remember for sure. My questions are as follows,
1-What brand of 31 splined axles are worth buying? There are so many imported and cut to fit ones anymore that it is hard to decipher what is best. Or do you guys think the factory 31 splined axles are sufficient? And if so does anyone have a set for sale? I am fresh out of stock 31 splined axles.
2- What is everyone's opinions on gear ratio's? Currently It has 28 splined axles and 3.73 gears. Figured that was a good combination for street and slight strip action and the car is not driven long distance. Or 3.89 or 3.91 ? I know not much difference than 3.73's But I have only ever ran either the common stock 3.25's 3.73's or way deeper gears when racing from 4.11 to 5.13's depending on the car, trans, convertor stall if automatic and engine. So I don't have any personal experience with those other gear ratios.
3-When it comes to gears, what does everyone think as to brands ? And do you think a lightened set of gears is worth the extra money since he wont be racing the car a lot, only occasionally.
As for the car it is a 1971 Mach 1 4 speed car with a fairly healthy 351 Cleveland making close to 500 horsepower that I built for him last year. My friend has just had his interior redone and bought another pair of magnum 500 rims that he put mickey Thompson drag radials on. He thinks he may break rear end axles when he gets the car to hook up, I agreed he might just do that.
I told my friend what I thought but said I would put the question to the group to get some more input. So please everyone give me your two cents worth and thanks !!
YLWHRSE

[hutchdude]

I buy all my rearend items at ringpinion.com . I have been buying the Yukon stuff, seems to work great! I went to 31 spline axles when I built my car. I have a Yukon limited slip.