Jonathan Yes, there are loads of Sierra diffs - some good information on http://www.super7thheaven.co.uk/components/sierra_rear_differential/ From what I can see, the LSD axles are on 4x4s and have flange connections. maybe LesG can let us know what he used and any issues, challenges, the end result, would he do it again, was it worth it.... I'm only considering this to save money, but if it gives a poor result I'll save for a bit longer .......