I was wondering what people have used for the centre push clutch release.

The box I bought has the cossie bell housing welded on (by MK for previous owner) there is a centre push in the bundle but it seems the main shaft in to the gearbox needs machining down to allow the smaller bearing and before I remove any metal I would prefer to use a bigger diameter centre push but not sure if that would work with the cossie clutch cover plate?

What have others used? Thanks in advance.