piston pin/snap ring clearance issue

[r lane]

In the process of building a couple of track engines, 3.6 and a 3.0. Apon installing the pistons onto the rods, I notice on both engines the lack of any lateral clearance between the piston pin ends and the snap rings. Of all the specs one has to consider in building an engine, I don;t think I have ever considered that other than making note that you could stick your finger into the bore of the pin and see that it would rotate. The manufacturer says there should be .020'' which sounds excessive and begs to ask what happened as this company has I believe a repute for a good product. A second issue, these pistons have a narrow skirt which creates a lot of crown overhang making snap ring installation a major pain. Spent a couple of hours making a tool that I didn't think would work and it didn't. A sleave the same bore as the pin bore to hold the snap ring and a driver to push it out. That tool would have to be jammed up very tightly and indexed perfectly for that to work, which I wasn't able to achieve. Appreciate any input. Thanks, Bob