I have an 04 Silverado 1500 with the 5.3 in it. I've been running pp 5w30 in it and recently I've noticed some blue smoke on start up, then it goes away. My thought is valve seals but I can't afford to replace right now I wanted to run some high mileage oil in the truck as it has 160k on it. What oil do you recommend? I was thinking valvoline full syn with Max life. Any other options?