Adinta, don't know the values, but AN should provide an upgrade path with the correct components. My dealer has offered to obtain parts and install them for me, or simply get the parts and let me install them. Kinda sounds like you are going DIY with this, yes? I think you can also contact AN directly or through triode and company if your local dealer can't.
Reading into your post, it seems you are asking if you can expect a difference. From experience swapping caps in my AN amp, I can say yes. I've swapped paper in oil, copper, and BGs and they do sound different (haven't had tried silver caps yet, $=yikes!). Also swapped resistors for tantalums and pcbs for hardwired silver. In each case, there's a noticeable increase in resolution.
One more thing, I have a 2.1x sig and a primary difference from the standard is tube rectification. If you can do this, there may be more of an improvement than just the BGs.
Please share your experiences if you decide to upgrade.
Hope this helps.