I think wires are getting crossed here between beam mount bushes and rear trailing arm bushes.
Beam mounts- go polly or solid alloy, polly for me.and a key to this is the diff mount-as it is one of the beam mounts!
Trailing arm bushes- some say polly are good, though the original ford designed spherical baring bushes are said to be best. These have been remade and available through GGR- but aint cheap