^^This^^.

I'd be willing to bet that you have the infamous failed LIM gaskets. For around $250 you can fix the issues and keep the motor.

What makes you think you blew a HG? Have you had a compression test done? I'd find it hard to believe with these motors, but I guess anything is possible. Heck, I'd be more worried about the trans going with that mileage before I'd even think about the motor.

Oh, and btw, I had 232K on my 00 GT and it was still running fine until it ingested a misplaced bolt