When these engines go kablooey and you know it’s going to have to come down, do yourself a favor and resist the urge to pull sparkplugs to scope the cylinders. The damage from the failure very often beats up the sparkplug electrodes pretty good. Removing it mucks up the threads in the head. We have actually seen it cause some very nasty damage that was very costly to repair. Below is a picture of a plug that the customer had sense enough to leave in place after a catastrophic sleeve failure. We were able to mill the exposed portion of the plug out and remove the remaining plug with no damage to the aluminum.
This failure occurred at high speed and the engine suffered crossover damage where shrapnel passed from the failed cylinder through the induction system over to the opposite bank.
LN Engineering did a great job saving the block and we saved the heads. This engine is back in service now stronger and more powerful than before.