i have a 1992 toyota supra single t67 turbo. i bought the car for 5,000 bucks and over the past year have but 5,000 into it with parts and labor. its a very long story but the motor has been rebuilt and i just got it back from the shop rebuilding the bottom end. i was driving today (same day i got it out) was fine around town, then drove it about 45 mins away to where i work, built boost ran fine. got off work and car was smoking really bad (white smoke) antifreeze is in the spark plug holes so my thoughts were head gasket. but it has a custom cermatic head gasket that was just put on not to long ago? ideas?