well here i go i have a 98 trans am whit a ls1 motor on it today i check my oil level i notice that on the oil tap there is some white stuff like mocues my friend told my that i have to change my head gasket my car has over 120k my car is bone stock and i dont know what to buy what brand and what alse to change i drive my car every day and off course hard lol any one out there can help me on what to buy plz