Here are a few pictures from when I did mine. In the first picture if you can imagine the rear skid, chaincase, oil tank, etc still mounted in the sled, you can see the top of the engine is accessible. In the second picture, a little earlier in the tear down to build process, you can also see that the head is well exposed, but from here the front sub frame assembly would still need to be removed. I believe if you were to raise the rear of the sled in the air to position the head in a more level position, would assist in making the alignment of the head, shim, timing cover gasket, etc a little easier...
I believe others have done this, I pulled the engine but I was going all the way with other mods anyways..
But this should give you a visual on how far you may need to go..