Importing specified subforums from a vB4 forum into an existing vb3.8 forum

[therother]

Hi all

I'm looking for advice on how to copy posts (~250k) in 9 forums from an existing vB4 forum (which I do not admin) to an existing but smaller vB3.8 forum (which I do).

I'm thinking the best method, assuming the admins at the larger site agree, would be for them to import their entire database into a clean forum (either a vB4 test site or another software that can import vB4) and then use the forum tools to prune the extraneous forums and users that haven't posted in the 9 forums in question, along with any other unnecessary/private data (especially PMs for instance). They could then dump the database and send it to me. I could then use an intermediate forum to do the downgrading from vB4 to vB3.8 and then use Impex to import the 9 forums into my vB3.8.

Has anyone got any experience with this? Is it a lot of work (the admins at the vB4 forum are nice guys, but I doubt they'd fancy spending days doing this)?

I'm planning to have a go using my vB3.8 forum to get a feel for the process, but would there be many changes for them doing it with vB4? They have the full vB4 publishing suite.

Any advice gratefully received.