When you pull it right down, remember to remove the "barbell" oil passage plug lower drivers side at rear of block....its under the rear seal case in a oil gallery....
Absolutely make sure you put it back in when building the engine. There are aftermarket billet units available to replace the nylon one from GM.
Seeing this has had oil issues and spun some bearings, I would also be align honing the main bores and all the rod ends to make sure they are all within tolerance.
Good luck...
