Ok guys, our size is an M8x1.25 bolt. Lowes stocks M8x1.25 in lengths of 25 and 30 (No, I dont know what the number means exactly, but its 25 and 30).

Both of those sizes are right around our bolt's length, give or take a few millimeters. The 25 is slightly shorter and the 30 is slightly longer. But, my guess is our bolt is the M8x1.25-25 bolt, and my broken bolt appears longer because it lengthens when you twist it as you're breaking it. Because its hollow it seems to twist like scrap metal as its breaking, possibly several turns.

And yes I just jabbed a kitchen knife into the hollow bolt and, due to the sharp knife edge, it grabbed the inside of the bolt and turned it out it easily.

The other issue is I read our bolt's are hollow because they relieve supercharger pressure, I think the oil or something. Its on a benz forum somewhere.... Some said it could be dangerous putting in a solid bolt. No pressure relief. I personally think its just to stop idiots from overtightening and damaging threads. So its possible putting in a solid bolt could be bad, but people have done it with no probs including the MB guys. Either way, I'm doing it.

Woody, if you look at your bolt you'll see a hole in the head. That hole goes all the way through.

And lastly.... My torque wrench only showed 23 ft-lbs when the twisting started. I was just about to stop tightening when all of a sudden torque was gone. I went a few more turns then snap!