Will an XS250 swing arm fit an XS400 SOHC frame?

[Bellerophon]

So I managed to get my hands on an XS400 frame to go with the engine I am rebuilding, but I need a swing arm. Most on eBay come from old XS250s. I know some of the specials had longer swing arms, but it is the fitment, more than the length that I am concerned about.

Cheers