Hi Marc,
The metal tubes that come with the kit are not usable on the GTO axle stub. I used the original ones that came with the ECS shocks. However for info the metal tubes in the kit are:-- Length 39.73 mm Outside Diameter 24.97 mm Center Hole Diameter 11.95 mm.
Just remeasured the original Metal sleeve on the shocks I removed yesterday :-- Lenght 41.45. mm. Outside Diameter 27.20 mm. Center Hole Diameter 22.01 mm. NOTE one end of the metal sleeve has a slight flare of 8 mm where it sits against the stub axle end.
When I initially approached a local machine shop to see if they could bore out the polybush itself, which I eventually did myself,they said that if needed they could make two sleeves out of stainless with no problem.
Any query don’t hesitate to ask.
B Regards
Derek