1994 Pontiac Sunbird Blue Smoke

Engine Mechanical problem
1994 Pontiac Sunbird 4 cyl Two Wheel Drive Manual

Just recently I replace the oil and filter in my car with 80% LUCAS engine oil treatment. A week later while driving down thru the rocky mountains and contantly gearing down, my car started to blow some blue smoke, then alot of blue smoke. Now it is blowing White and blue smoke although engine poerformance has not been affected. I am trying to determin if I blue the engine, the head gasket or could the drain back holes just be clogged. The smoke only blows when I accellerate. And gear down.

thank you