I had got this Pioneer/Partner 400 a little while ago from a friend. I want to get going on cleaning it up and want to replace the sprocket with a rim kit. If you look up a 400 on Oregon's website which is only listed under Partner and not Pioneer and there is no Pioneer/Partner listing it says to use 35641X. Now there is a P400 listing and that uses a 29175X. Both use the same sprocket brg and both use the same .325-7 rim. Which sprocket is the right one? Here is a pic of the serial # plate and decal on the side.