Dirty Howie

Well there is your answer. I have never heard of anyone using that oil in their LS7.

Thickest I have heard using (and sometimes recommended by GM) is 15w30.

I use Mobil1 0w40 and recommend it highly (you can find a thread I posted which has my Blackstone reports)


DH

09C6Z06

Just had the same issue with my 09 38k miles. They replaced cam lifters rockers (i thinks 8) it sounded like a rod knock not a cam. Spoke with an engineer from GM performance who warned me not to put anything more than 5w30,he said the tolerances were too tight for higher viscosity oil funny I didn't notice a loss in performance but she's a lot faster now

dreskiluv

Let's hear what the engine sounds like now