Gentlemen, My brother and I are both building ST3s. They are coming along rather well. I have seen a lot of postings about the bushings. I got my from
Kartek Off Road - Where Off-Road is On!. They have exactly the size that is needed for the build. Incidently I see that a lot of people are using the Subie rearend with shaft drive engines. We are both using shaft drive engines. For the differentials we are using Eagle Talon LSDs (got mine on Ebay). They fit really well.