Most of my BBC experance is with marine builds. Most of the time number 7 cyl fails, next most often is number 8 cyl. So this was in the back of my mind, was one of these cylinders were it failed. Usally a valve hits a piston with little evidence as to why. Have my thoughts about it.

High load conditions with a solid roller is an issue initself as many of the valve train componets need checked and replaced more often.