i need to know what oil is recommended for my car. I about to change oil for the first time but not sure what to put and i dont know what the guy before used. The motor has 9k miles on it. Its a gsr head on an ls block w/ eagle rods and je11.5:1 compression pistons. My bearing are also going out and the car leaks some oil. Im thinking a thicker weight like 10w40. I think the guy was using 10w30 before.