One of the first roots blown Littlefield) (10:71 Hemi I built and dyno tested made 7.5 lbs. of boost with 12 % underdrive at 7300 RPM with 33 degrees of total timing on CA pump swill in 2002 or so. swapping the pulleys ended up making it have 13% O.D. and that made 12 Lbs. of boost at 6500 RPM and pick that motor up 100 HP on race gas with 25 degrees total before going into detonation
Every combination is different so I try and tune off of the spark plugs and time slips at the races