The tailwheel spring came with two 1/4" holes at the rear to connect to the tailwheel and one 1/4" hole at the front which needs to be a 5/16" hole in order to match the hole in the fuselage. Mark Goldberg said that the next batch of tailwheel springs will come with the front hole already at 5/16" but until then, we need to enlarge the front hole from 1/4" to 5/16" to match the fuselage.
THE PROBLEM - Before drilling the hole out to 5/16", I mocked things up by installing it with a 1/4" bolt in that location. When rotating it within the limits of the 1/4" bolt in the 5/16" hole, I could see that it went further one direction than the other. This meant that the tailwheel would be rotated slightly clockwise when viewed from the rear. Using my digital angle finder and comparing the side of the wheel to the vertical post of the vertical stabilizer, I determined that it was about 1.3 degrees off. That may not sound like much but it would move the bottom of the tire about 3/16" off center. Looking at the different pieces, my calibrated eyeball told me that most of the error was in the angle that the two holes were drilled through the receiver socket on the tailwheel.
THE FIX - Since I had to enlarge the front hole in the spring anyway, I decided that the easiest way to fix the problem was to make the 5/16" hole at a slightly different angle than the existing 1/4" hole, specifically 1.3 degrees different. I clamped it up in the vertical mill and ran a 5/16" carbide endmill through it and brought it home. It went together nicely and now my digital angle finder says there is only 0.1 degrees difference between the tailpost and the wheel. I can live with that and it is probably within my margin of measurement error anyway. The picture below of the tailwheel mounted is after the fix was implemented.