Sorry 106 is lobe center , they didnt give lobe seperation .
-beerjet-
It's probably a 110 LSA with 110 lobe center, but ground 4* advanced, giving it the 106 intake centerline.
As far as cutting down the impeller to gain RPM, you will only gain from that if you are making more horsepower at a higher RPM than what you're making at the RPM you're currently running, which I'm thinkin' your motor probably tops out somewhere around 5500RPM so you very well may gain from cutting the impeller down with a slight sacrifice in holeshot.