i could believe that.
if the stock airbox had that ramtube left in it ( as if one could get it out )
considering that design really its the same airflow as all the others , pretty unrestricted. only thing it might have going for it is the amount of free space in the box itself , i have read a .8 cc airbox volume is ideal per cc engine displacment. roughly measureing the snorkle between the tbodies and the airbox that volume is just shy of what would be needed if the above holds true . considereing any volume up into an airfilter i figure puts it in the good.
the snowpro ( bdx/sw) airbox is about the same but the cover i dont think is sealed as tight as a factory unit but its kind of the same deal as the cpc set up where there is a coverplate in the nose creating a semi airbox.. aprox same volume as stock. d&d is open in the pics i have seen , as is TS?. one could easily cover both with the oe snowpro nose cover though to create the same effect.
basicly the route i went design wise, (home made manifold, unifilters,oe nose cover,oe beak screen, oe airvent screens,cpc sidenose and pto side shock tower frogskin vents) put this set up on 2 sleds with a few differences between them ,,