i have all ways heard that alittle vavletrain in the LT1 is normal but i have been hearing alittle more lately. It seems to me that it comes more from the driver side and from the underneath it is really loud right under the exhaust manifold around the 7 and 5 spark plug. But no leaks check and checked more cant see anything and cant feel anything. It seems more evident warm but not warmed up all the way to 180 and sometimes really evident when the temp is about 200 or 225. The car pulls good and compression, vacuumis great.Also took the valve covers off and they sound really goood and lashed a couple that were alittle noisey, but still no change. I have been messing with differnt types of oil like VR1 40w and looking in to mobil 1 0w40. I ran 5w30 synthetic but it was to thine for me like water . So right now i have the VR1 40w it seems good and stuff, but i was told it was bad for the LT1. could it been oil ????? The guy i bought it from was running 15w50 mobil, I though it was too thick. IDK hope you guys can help tell me if it could be oil related or is there something wronge? thanks for any advice!