Was that my boat? LolPretty sure there are two of us that have broken 100 with the XB-21 ProSports.
I did it in 2007 or so with a 300x, 1.62 gears and a 27 Trophy prop @ 6800 RPM's, by myself with a light load, 24-V T/M, 3-27 grp batteries etc... No set up time, first pass with the boat after installing the 2001 year model engine I had sitting on a stand. Never got to play with it again, sold the boat to one person the following week, and the engine to someone else.
Pretty sure whoever else it was ran 104 with pretty much the same setup.
The 300x engine was a beast, true 330 hp out of the box.