Bahnsey, I have an 83 barrel with a liner at 87.50mm or .060 thou (std is 86mm) the condition of the barrel is ok ,just missing the piston assy.From what I can tell it is not electrofusion bore (as I can see hone machine marks on the inner sleeve and I can see where the ports have been aligned,maybe LA sleeve but not certain.I have looked at the Serco catalog for wiseco and found the 575m08750 .060 87.5mm piston kit BUT it only starts the model range at 1988 and not 1983.