9'' rear help

[FORDification]

You just need to make sure you get a third member for 28-spline axles, which is what the '67-'72 trucks had. (The '73-up trucks got a 31-spline axle.) The axle ratios you mentioned are the best compromise between street and strip.

As you stated, you'll need a gasket, but other than that you should be set. However, since you have to remove the axles to install the new third member, I'd suggest replacing the axle bearings at the same time. They'll have to be pressed off the axle, so as long as you already have them out, now's the time to do it.

[gonzalo medina]

Sweet deal thanks for the help I will go head and purchase a unit.

[68F250]

Better count your splines 'cause I believe 31-spline axles started showing up in '69. Also, some trucks got the funky 9 3/8" pumpkin which was also used in the T-birds and Galaxies. All those were 31-spline too. If you got the 9 3/8" toss it and go for the 9", it's a lot better and fits the housing.

[FORDification]

Well, I decided to actually spend a few minutes going over the Axle Assembly Identification - Ford Products to check the axle spline question out. I see that some '68-up trucks did indeed have 31-spline axles, but only on the trucks that had the 9-3/8" rearend. If it had the 9" rearend, they all had 28-spline.

However, now I'm going to have to research this 9-3/8" piece, 'cause up till now I've never even heard of it! Interesting! So how would one differentiate (no pun intended) between the two?

[fordman]

i never heard of it either. i'll check out the mitchell manualls at the library too next time i'm there.

[68F250]

So how would one differentiate (no pun intended) between the two?

I did a quick search on the net to find a picture.

http://hotrod.com/techarticles/48618/index13.html

Look for the curved rib on the top.

So no 9 inchers with 31 splines? Even the 4x4's? I'll have to check that out later, gonna be hitting the road now.

[Pro-Street/StateTk]

I read the hod rod artical a long time ago and while talking about it on
another site I came up with this site!



http://dfwmotorsport.com/Fairlane/9inchrearends.htm


P.S I have worked on 73-79 small block and inline 6 f-100s for years and
I have never ran across one of them that had a 31/ spline rear end, but
some one told me that they had only work on big block f-100s and all of
his were 31/ spline. So 28 spline = small block, and 31 spline = big block or 4x4 .