rebuilding rear end: handful of questions. # splines? teeth of speed wheel?

[BerniniCaCO3]

So! I've resolved to rebuild my rear end. I want 3.73 trac-lok/ posi/ limited slip rear gears, possibly 3.55. Not 4.10; too extreme!
Right now I have a 3.08 open rear end.

First question: 28 spline or 31 spline? Would an explorer or mustang rear axle work, to donate all the parts (and then I'd get a rebuild kit for the clutches)? It seemed that units were either 28 spline, or 31, and I don't know what I need-- before I run off and buy a mustang axle.
I assume I'd want c-clip eliminators (coworker advised)?
If I went ahead and replaced wheel bearings, too, are those straightforward? ...are they press on, such that I'd have trouble doing them myself?
for 3.55 and for 3.73, how many teeth do I want the speed wheel in the trans housing to have, so my odometer is correct?

And to be sure, I would need that center assembly --the limited slip differential itself-- and 3.73:1 ring and pinion gears? Or with the posi differential, it's just one whole unit and the ring gear is built in?


thanks!
-Bernard

[BerniniCaCO3]

it looks like I want 28 splines...?
are all mustang axles 28 spline?

I have a 1990 colony park wagon, if the wagon had anything different from teh GM sedans.

[Mercracer]

Explorer was 31 spline.
Mustang was 28 until ??2005??
Explorers had 3.73 as a common gear. Mustangs did not.
DO NOT try and use C-Clip eliminators on your street car. You do not need them unless you are side-stepping your clutch at 5500RPM.

[BerniniCaCO3]

thanks! mustang rear it is, then.
coworker said to get 'em. Sounds like I have no need for them- but what are the disadvantages? (just wasted $?)

[BerniniCaCO3]

and, our grand marquis' ARE 28 spline?

[Mercracer]

All 2002 and older are 28 spline for certain

[sly]

c-clip eliminators make it easier to change axles and the associated bearings without having to tear open the pumpkin every single time. rais up the side to be fixed higher than the un-eff'd side and then you'll prevent spilling fluid as well. swap out crap, drop it back down... top off the pumpkin from the fill hole.

Other than that, on a stock/street build... meh. If you're having a 400+ HP setup going, it might be worth thinking about... but until you get into the area of really needing to swap to a 9-inch rear... it really shouldn't be an issue unless you're using crap parts.