See link above to dyno data. The BSP4 makes power higher in the rpm range than the BSP3 does. The BSP3 falls off after 5600-5800 rpm.
I want to say that the BSP3 was circa 2014/2015 (could be wrong there) and since then the effort has been to ever increase the usable rpm range with 10.8 lbs springs. Back in its day, the BSP3 was a good cam, but continued development has rendered it obsolete.
There are two separate pulls on the BSP4, one with a 111° ILC install and another at a 113° ILC install.