Hi. i have an 84 gmc sierra, 305ci, 4 speed manual, and sometimes when i start it up in the morning a lil puff of white smoke comes out, and any time im in high rpm (mostly when in second gear hauling ass) it pours out white smoke but only when hauling ass. this oil leak seems to be comeing out of my rear most passanger side exhaust port and into my long tube headers. but even thow theres alot of smoke my oil level stays the same pretty much and my oil is gold even after 3000 miles. everytime i do my spark plugs there all always covered in oil. the motor runs good just that smoking problem. im thinking its either piston rings or valve stem seals