I like the 57H alot. The only issue I have that I haven't corrected yet is the thunderheader torque dip at 2500-3000 RPM. The cam definitely pulls hard from 2500 and up. Butt Dyno is Night/Day.
The cams are in a 2011 RGC. I did S&S Lifters, S&S Push rods, and the zippers dual cam tensioners with the oil bypass. I have a direct link tuner key and I still have a SERT. Currently running a 2-1 Thunderheader, considering a D&D Fat Cat. I would like to leave the cam chest alone. Maybe do heads and a new pipe and re-tune. Not sure if the 57H will perform well with a 107"?