Bug killing smoke!

Just bought a 86 GN with motor problems. The last owner ran it hot (fan relay problem) limped it home, leaving a trail of smoke, parked it there and it sat for almost 2 years. I got it to my house, drained the fuel, checked the fluids, clean oil and coolant. Put a battery in it just to see if it would turn over, and to my surprise if fired right up.I ran and sounded great, after approx 2 minutes it started smoking a whitish smoke, but no sweet coolant smell. Not really oil smell either. Smoked really bad, I shut it down, pulled the plugs, none were "bleached white" due to coolant leak, they were all a little too dark but not oil fouled. I decided to pull the heads cuz everyone I talked to said this is the problem, and as I pulled the second perfectly sealed head off, I knew this wasnt the problem. I'm sending the heads out to see if they are cracked, check seals/seats and get a valve job and ported while the're off. Could a bad turbo seal cause this terrible smoking problem? Any help with this issue would be greatly appreciated. Thanks in advance, Ken, Lancaster NY.