I see several methods...
Use thicker oil or even grease on those areas. (Easiest option)
Solder the area and hone for good fit. (This is the best results but you will burn your paint.)
Sleeve them with brass tubes (actually works pretty good but you have to find the right size tubes.)
Use J-B weld to make up the gap. (I don't know how long wearing a J-B weld is the bearing surface...)