Did an engine swap on a 172 with new clutch on Monday. Started at 9am... by 12.30 engine was on the floor, box off, new clutch fitted and it was in, fluids replaced and running again for 17.30
Admittedly swapping ancils and brackets does add loads of time though but compared to the Mk1's these are simple.
Dan, the A/C pump and even the PAS systems don't have to be drained/opened up. You can leave it all connected up and let the ancils hang in the bay and pull the lump from above with ease