I have the whole K&N she-bang
The 14x4 or x6, with the X-Stream lid, K&N Oil Breather, K&N Oil Filter....
All seem to work well....
I had to modify the under side of the plate on one side of the carb filter and the filter slightly to clear the hose fitting to the carb without kinking, and this was easily done with needle noses with the K&N because of its wire mesh backing.
I still need the flow straightener to have "the whole deal."
I guess all that ran about $180, but it does breathe well, although I'd like cool air brought in to it rather than just maximum amounts of whatever's under the hood.
I believe the Accel or Holley blue colored one is equivalent, but haven't tried them. It seems to me it only makes sense to minimize intake and exhaust restrictions on anything wherever possible, and this set-up is rated at something like twice the flow rate of the carb....