Just to be clear - The details:
I ran dynos on the same machine with the same operator (Nels Byersdorf owner of Two Wheel Dyno Works).
The K&N dyno (161) was in the summer. The RamAir dyne was n the fall (157).
Nels said he had to add fuel with the RamAir, which meant the RamAir breathed a "little" better in spite of the lower HP reading.
He attributed the slight difference to atmospheric conditions.