True, the seals would take care of preventing leaks. When Welder Guy & I were contemplating the mod, we decided that since the mating surface of the axle housing was machined, that it was best to grind the welds in that area smooth.

One caution (forgive me Lord for agreeing with Zeus on any matter) - Check the tightness of the bolts that hold the axle housing to the diff brackets periodically. They can work loose over time & that's exacerbated by the fact that you've significantly decreased the mating surface area. Some locktite on the threads would've been a good idea but we forgot to tell you that (hindsight it 20-20).