Do you think the pinion will twist or the gears break? The reason I ask is because the front drive shaft is about 1.125" at the slip yoke and the dana 44has a pinion diameter of 1.376".
Look at what most of the other diffs use for a pinion shaft diameter. The D44 is small in comparison. What will happen in this case is that the pinion shaft will flex by the gear end since there is not a third bearing to support the pinion. Having the third bearing on the pinion is how the 9" based diffs survive so much abuse while still having a small pinion shaft diameter.
If/when the pinion deflects, the gears will break. I doubt a pinion shaft will snap unless there is some severe wheelhop or poor suspension setup.
What I have used in an off road application is a high pinion Dana 44. This is stronger because it is a "reverse rotation" ring and pinion; when driving forward, a standard or low pinion front axle is really driving on the coast or "backup" side of the ring gear. This tends to make the teeth break off the ring gear, because it is much weaker.
That isn't why the high pinion diffs break the way they do...
Can't you also find softer R&P to handle power better? The ones that are drag only stuff and never to be used for anything that racks lots of miles.......
I've never seen a set of the soft gears for a D44. They would probably have to be custom made, but if you have enough money you should have no problems getting some. The other thing to remember is that the material used in these "soft" gears can be hardened to any hardness you want. The same material is used in the gears made for nascar as the soft drag race gears, just hardened differently.
A couple of things to think about:
1. The mid '90s trucks had D60s with 30 spline axles. D44s use the same diameter 30 spline axle. At best, the later 32 spline axles used in the 60s would be a slight improvement but I wouldn't expect much.
2. The u-joint in a 60 is HUGE compared to that of a 44
3. The pinion shaft in a 60 is quite a bit larger than that of a 44.
4. The ring gear on a 60 is obviously bigger. This makes it possible for there to be more tooth contact between the ring and pinion. The Ford 9" has a bit of advantage here since the pinion is more offset than either the 44 or 60, which allows more tooth contact in a smaller package.
All this said, I think it will work but you will probably be on the edge with it. Especially if using slicks. An automatic foot braked car will probably give it the most chance of living. If you can afford it, I'd try to go the 9" route. It will be substantially cheaper if you can do the work yourself, but still more than what you would likely have in a 44.
