Bad reluctor or RPM's

We run a 3000lb offset pavement late model and a sub driver destroyed our engine this weekend. The car was popping and not running correct so we changed the msd box, coil, carb ect... The driver was instructed not to run over 7000 rpm's as we were trying to find the engine problem.

On saturday the driver took the car out and ran my engine 10 laps at 8500+ rpms and claimed he wasnt told before hand and didnt hear any of the radio communications. I told him at that minute he undoubtably hurt my engine with those rpm's and he denied it would do any damge. That night I put in a 7K rev chip and cut apart the filter. Inside there were a couple of small pieces of something but nothing that concerded us.

The engine was a 4 bolt 010 block, splayed capped, wet sump Canton pan, Callies crank, Oliver Rods, Ross pistons, Dart 200 Heads. 3.50 stroke less than 50 laps and some dyno time.

We were rained out and returned Sunday. During the shake down we found that the Distributor has sheared the reluctor pin as was freely spinning. Believe it or not the car ran with that problem and was hard to find.

After 4 warm up laps, the engine spit the front of the crank out of the block and took the main caps with it. Great advertisement for ARP.

My question is what most likely killed my motor? Extreme RPM's or the reluctor on the distributor coming loose.    

No Facts just my opinion that with the sheared pin motor was running slightly out of time and with those rpm's that is what hurt your motor as I had a similiar problem but caught it before engine failure.  

I think what Rebel means is that both contributed to the failure. But I got to wonder with the way it broke if the RPM and vibration, from being out of time, didn't hurt the balancer or crack the crank.

If I had way more details I could have a better educated guess!

I had a outlaw motor break last year the same way. It turned out to be an issue with a flywheel. The car owner/driver stuck a ext. balanced flywheel on an int. balanced crank!!!  
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