I have used these:
http://www3.towerhobbies.com/cgi-bin...&I=LXD610&P=SM
for 1/10th scale and they have very little slop. I know someone makes them in larger size for monster trucks (can't remember who though). That should be tightest setup you can get. I just keep a big supply of ends and replace them often on my Mayhem buggy.