...I hate to say this but signs point to internal damage** Being around highly modded turbo cars all my life I can tell you that a mere blown turbo will not cause a motor to overheat as seriously as yours. *It might not be the turbo at all * I think you've either cracked a piston, or more likely, the piston rings are shot. If it were just a head gasket issue you'd have clearly white smoke along with some condensation (being that coolant is being burnt). I can even smell the anti-freeze in some cases on cars with blown head gaskets. But if your saying that your getting clear and honest blue smoke in large doses WITH overheating as well...thats a clear internal issue. I guess after all the years of boost on the stock motor its finally started to let go...
If thats the case rebuild with forged pistons with a beefy turbo friendly head gasket and bolts too...you might as well fortify it for higher boost
