I am aware of 3 types of trailing "arms"
Worst of the lot are the solid bar type, introduced as a cost saving in the 90s and thankfully NLA
The standard tubular RRC type also found on most Defenders, all EAS RRC (with the extra tabs) and the type now stocked as replacement, whether OEM or Britpart (something they make well :clap:)
The extra thick 110 Defender arms, not seen very many personally (I understand they were sought after at one time) and also NLA, being superceded by the standard arm.
Lengthwise I think they are all the same, unless you are talking about after market/cranked arms. All later ones are M20 at the chassis end and take the same size bush at the axle, AFAIK.
