Keep digging on the autopsy to determine what actually killed the motor? Instinct is oil pressure/bearings problem. Put the crankshaft 'stroke' concerns on the back burner. Your motor configuration sounds fine, get together with Cab (He'll see this and should contact You thru IM) over there in Bend, OR and make a durable motor. This 'racing' stuff is painful some days. Remind Yourself: It's only money.