I did a head gasket on my 87300D a year ago (thought I had a bad gasket, but was a loose oil plug, back side of head) and would tell you it isn't that big of a deal to remove the head. Bet it wouldn't take but 1-1/2 hours to get it off (helps if you have a hoist)

Transferring the exhaust manifold W/turbo attached to a replacement head wont take too long either. It's a full days work, and the really only hard part, not really all that hard, is torquing the head bolts, everything else is easy, really!

Consider doing it yourself and save $3000, people here will guide you.