Sorry to hear this GAV the last time I heard of a LS motor suffering that type of damage was in my sons Maloo after he gave it a hard time, when we pulled it down I found some thread tape in the crank
oil journal which none of us had any idea where it came from maybe a
oil temp switch or something luckily a regrind and new bearings fixed it but a whole lot of work at the end of the day. Hope it all goes well for you and that its not to terminal.