Big-bearings are better than small-bearings for the obvious increased load capacity reasons, but most of the mid-size sedans came with small-bearing housings similar to the Ford 8" rear ends. You have two big-bearing options for OE style housing ends, a ball-bearing and a SET20 tapered roller bearing. Each has their pros and cons, but the SET20 does have a higher load rating, especially when comparing axial (side) loading.
Standard axle splines are 28 and 31 for the Ford 9's. Only a few of the performance cars, full-sizes, pickups and vans got the 31 spline axles from the factory whereas most of the mid-size cars and early Broncos (66-77) had 28-spline shafts. If you go aftermarket, you have 35-spline and bigger options, but those will require big-money and full aftermarket housings, center sections, etc to fit them.
Since the Ford 9" housing is fabricated mild steel, welding brackets to it for 4-links is typically much easier than a cast-center type axle housing such as a Dana, GM, etc.
There are more than three housing ends to worry about, but the three mentioned above (small-bearing, big-bearing, and the new style "Torino" big-bearing) are the most common. If your friends 9" is under an early 60's F100 pickup, it may have one of the not so common housing ends and brake offset dimensions, so buyer beware.
Tobin
KORE3
|
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
Linear Mode
