sorry since some one already said.. this design will not run better then stock inlet.. the adapter plate is will reduce the air flow. TVIS inlet run 8 port it can help the air flow better, but ur custom one with single port but air will hitting the adpater plate before entering into the head the speed of air will highly reduces. maybe u can just porting the inlet plate and throw away the 8 hole make into 4 and must match it right and same size of the head port so that it flow better.
the air box also not big comparing to the stock wan.