You used the ring manufacturers suggested gapping which is wrong for KB hypers. I've seen KB's rip the top of a piston off in normal street driving using the .004-.0045/inch gapping most ring manufacturers recommend.
The gap on top ring for a 360 should be in the .026 area for street driving.
It's a grenade waiting to go off running juice on that ring gap. Gap for light juice use is around .032 for KB's
See the second page for ring gap factors.
http://kb-silvolite.com/assets/kb_installation.pdf
