Quaife ZFQ main shaft bolt

[Cy]

I have an earlier ZFQ E62G41 and from what I've read it probably has a machined main shaft bolt and that they now use a forged bolt that would be an upgrade. I emailed Quaife and received a responce that stated they only have a machined bolt for that part. Has anyone sourced a forged replacement bolt or know who I could contact about this?
Thanks
Cy