I have an 83 with detroits, low gears and 38s. I started with 33s and e-z lockers and a double case and broke 2 birfields in about a year. Next was 36s and a 4:1 in one case and broke 2 more birfields in a few months. Next I got Marfields (now I'm showing my age!) for a competition in 2000 and broke one the second day! It was warranteed and lasted till 2002. The other finally broke in Aug. 2003. Now I have Longfields and 38s. One longfield is about 1 1/2 years old and the other is almost 1 year old. I've limited my sreering a lot and run in 2wd a lot and am a much better driver now. so we'll see what happens.
In my opinion, the way to save birfields is to have a selectable locker in the front, max out the steering stops and try to keep the wheel straight when in a bind and never back up an obstacle or pull someone else backwards. (use the winch or turn around)
