The Fasen Raven uses an IHC fork and IHC compression with a standard diameter clamp and standard diameter bars. You wouldn't be able to use any oversized bars without changing out your fork, clamp, and compression system.
You might technically be able to get oversized bars to fit IHC by using the IHC shim and the HIC shim, but that would create a very unstable system. I do not recommend going with this method. If you want to use oversized bars, you need a standard fork and HIC or full-size SCS. If you want to use IHC, you need standard diameter bars.
It's sorta-possible. Some bar builders have done what they call "tapering" bars. This is the process by which a larger, oversized bar (pipe) is welded over the standard diameter bars that have been cut shorter. Essentially, it makes the bars look like this terrible diagram: