Never blew one up.. start spinning.. shift the damn thing.. on and
off the gas is just about a guarantee to blow a sprag.. thats a big
slam into the sprag ramps.. when you spin the sprag you start
to spin the drum 2.2 times faster than the engine RPM.. being
the the 727 is larger in diameter it will only take so many RPMs
and it come apart at ABOUT 13000 rpm.. a 904 drum is smaller
in diameter so it can go to higher RPMs