Before we all get excited...please understand that there are several different factory Ford "N" housings.
The famous, high performance, heavy duty 9 inch housing from the 60's is the C4AW-4025-B case. This is a very desirable, 3.063 big bearing case. This is the one that is very expensive and well known. It will usually have the Daytona pinion support, and it may, or may NOT have a big "N" cast in the front. The no "N" N case is very desirable, and hard to find.
In 1970, Ford produced the D0OW-4025-B case. It might be a heavy duty case, but not high performance. It can be found in some 1/2 ton pickups, and I've seen them in ambulances. It is a 2.891 small bearing case. It does have the big "N" cast in the front. It is stronger than the C7AW-E case, but with a standard pinion support.
So...you have:
1. C4AW-B "N" case.
2. C4AW-B "no-n" case.
3. D0OW-B "fake" case.
Please don't take "fake" as meaning bad, or weak. It just means that it isn't a true high performance case from the muscle car era. It's "fake" because it isn't as strong (and numbers matching) to a Shelby, Boss, Cobra Jet, Thunderbolt, etc. application...and you can't tell from the outside!
For a Bronco 9 inch, 4.10 and higher...I would rather have big bearings and 35 spline axles. So any aftermarket 3.25 case would be a stronger combination.