9 inch rear axles & gears

[ylwhrse]

Post: #6
RE: 28 to 31 spline axles

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, converter 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
P.S. I posted this question in another spot instead of a new post. So whats everyones opinion on this ?

[Mustangmike]

If you are not going to race the car the factory 28 spline axles would do the job and the factory 31 spline axles are probably more than sufficient. Curry offers new 28 and 31 spline axles and they seem to have a pretty decent reputation in the arena. However, I have not done business with them.

As far as gear ratio, I am running 3.89's in my car with a close ratio 4 speed top loader and my friend decided to run 3.50's as a better match up to his wide ratio top loader. Both of us are using original 28 spline axles and since we both will not be racing our cars, 4.11's and up don't make much sense for us.

As far as a manufacturer, I always look for the best deal and at the same time like to stick with names I know. In my case, I ended up purchasing a Yukon ring and pinion gear for my car.

Hope this helpful.

   

[ylwhrse]

Yes that's pretty much what I told my buddy. I guess he just needed to hear it from others. Thanks
YLWHRSE