I pulledthe front rockerbox assembly off to modify the return fittings, and see how everything was wearing in with each other. The rocker pads that hit the valve stems were centered, the custom rocker arm thrust washers were holding up well, and the shafts were good too. This is a really cool pic, there are not very many bikes you can do this with.
Here is a 38 to 47 fitting compared to a 36/37 fitting. See the difference in the hole size. It is a .030 difference. My bike has reproduction baby food jars on it, and they have the later style return lines, I figured since the lines were bigger, I should run the later fittings. I think that modifying the fittings will help me make the bike a little more oil tight. I will know this weekend.
Here is a pic of the modified fitting. I brazed the end of it, then I drilled it with a .090 drill in the lathe, then reinstalled them. The logic behind this is ----> 36 and 37 ELs
have the same amount of vacuum
as later bikes, I think that the smaller hole will make the suction stronger, and hopefully suck more oil out of the baby food jars.