Here is the reply i got from Siebenrock. If this make sense...
Hello Georges,
asymmetric means that the angle from intake and exhaust is not the same. So we can use the maximum of spread.
In sum is it a 320° camshaft. You have about 7-10NM more torque and + ca. 3HP
Mit freundlichen Grüßen / kind regards
Ralf Martin