I would say it depends on what the book time is for pulling the engine, if in fact the engine has to come out. If it's 8 hours book time for just pulling the engine, and then you add the book time for doing the repairs at a $100 an hour shop time, that adds up quick. I'm thinking the engine would have to be in almost perfect condition to pay all that money on labor and not replace it.
Not sure where you are finding a $100 an hour shop rate. Around here it's about $200 even at most independent shops.