When injectors are worn, they leak fuel and that fuel winds up in the crankcase and dilutes the oil. Common problem for the LB7 engine. Suggest you look in the LB7 section of this Forum and read several pages of injector problems.
Sorry, it should not happen, but that is the facts.
Chevy 04.5 LLY, 2X, shell, XDR, MikeL Heavy duty up-grade, 6spd, TransGo, deep pan, de-badged, 65 Gallon replacement Aero tank, LBZ-mp, Kennedy pump, shimmed, Pre-fuel filter, tow mirrors, BU cam, gauges, GPS, Sirius, bags, custom grille, fender vents, HD trans cooler- Curt front hitch, footwell lights, load lights, Studs, head gaskets.--- Jerry