I've been working with Stavros on this, and it's pretty frustrating.

The pan is not perfectly flat, slightly warped back near the drivers side mount. But's not bad, maybe 1/16" of an inch off flat in the corner and no visible bend. We've been using The Right Stuff, overnight cure, and wire wheeling the surfaces clean each time. All of the taps into aluminum have been helicoiled for extra strength.

I have a spare oil pan, which I will check for flatness. If we try it again, we'll certainly pull the tie rod off one end of the rack so that we can lower the subframe off completely (the rack was preventing it from coming down off the car).

Dave