I know my mechanic took two days but that included test driving and a quick check on everything. So two days max with a shop that doesn't have to send stuff out. He also is a machine shop so everything is done in house which saves time. He also has special order accounts with part places so he usually can get stuff fast which also helps.

 

I work in my own garage in my own HHR, so I know it's done right the first time!
Last engine swap was a new long block from Summit into a friends 2007 2.2 automatic, I started at 8 am, had the engine out by 10:30 am new engine installed by 5pm. Running and back in her driveway at 8:30 pm
So, it can be done in one day, just bear down and grunt!! Then again, I don't have the phone ringing or customers coming and going!