The head needs to be planed flat at an auto machine shop. They should only need to remove 0.010 or 10 thousansths of an inch, approximately. More than that indicates the head was REALLY warped. Ask for their evaluation of the head. Try to give it to them in as clean a condition as possible- use lots of degreaser, like Brakleen by CRC. That'll save you $$.
The hardest part probably is getting the exhaust manifold nuts off. These 8 nuts will cause you more headaches.... the best way to approach them is lots of PB Blaster, then SPLIT the nuts with a small chisel. DOn't even try to remove them until the nut is released from the stud by splitting it. If you break the stud, the machine shop will have to replace it and that costs more money, especially if you snap it off flush with the head.
Get a complete gasket set from FCP Groton or similar, and buy a Fel-Pro brand head gasket- they are superior and for the turbo, you always want the best.
Figure on replacing the waterpump and timing belt too unless they're new. Install new front engine seals (you'll be replacing the cam seal anyway, right?)
If this takes more than a day or so at the machine shop, cover the top of the engine to prevent rust due to exposure of the internal surfaces. Never let water sit on the exposed engine block.
With the turbo, you might find it easier to disconnect the exhaust and remove the turbo, manifold, and head together- you'll need a little help because it's heavier but it should make it easier to get the manifold nuts off. Have a place ready to set it down- like a table covered with newspapers or something to protect the bottom surface of the head.
Enjoy!
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Rob Bareiss, New London CT ::: '86 244DL- 215K, 87 244DL- 230K, 88 744GLE- 198K, 91 244 180K