I can't say, but it took me about 3-4 hours to do mine. I did not bottom tap and did them with the head in place. I swapped one stud out and one stud in, then torque. Rinse and repeat 25 more times.
The post valve adjustment would likely be from the flat rate book, but I would think the stud installation would be just on the time it took.
You should probably look at least one re-torque, which would also include a post valve adjustment.
Jim