I will take time and share what I know about these old units soon. A quick rundown on your 47. It doesn’t have seals. It uses slingers. So they seep a bit no matter what. You can adapt modified sealed bearings. But it’s not really worth the work in my opinion. The 47 is not an overdrive unit. About 1.5 and 1.25 under. And direct. Great for splitting gears to give that little six a fighting chance. I have a Watson 45 in a 46 Chevrolet two ton. A 39m in a 65 gmc k1500. A 2021 in a 60 gmc c1500 with a hydramatic. As mentioned the parts are non existent. And some of the bearings are not available. They benefit from getting the pre load back and run a lot quieter. The input and output bearings are notorious for wearing quick as they don’t have enough oil to really run cool and it’s important to keep the oil up and even slightly over filled. These things leak! So it’s an important thing to keep up on. These 30 and 40 series Watsons were designed over 80 years ago. Remember that. They really dislike 60 + mph…. High speeds and the oil gets hot and whipped up. And it overwhelms the slinger system and then they really leak.