I plan 1 headstud job a week to be able to handle my work load in the other bay as well.
Customer drops the truck off, I completely flush out all the old coolant. Pull cab, pull heads, take them to machine shop. That is day1.
Day 2 I clean/tank/wire wheel anything that is needed, get the new parts in from the dealer and prep the block and pull coolant plugs and drain.
Day 3 hopefully get the heads back. Put it all back together and put the cab on. Maybe start it if I work fast.
Day 4 Start the truck, continue to flush coolant, reinstall with CAT. Test drive the truck. Take it home that night.
Get a bunch of hot-restarts on it, a few cold starts on it.
Tell the customer to come get it.
That's how it's supposed to go... or scheduled to go for me. If there is warranty involved, the customer is constantly low-balling/pricechecking/lowballing/nagging you it takes longer and disrupts your abillity to get the job done.
The absolute best thing to do is talk to whoever you're taking it to. Get comfortable and let them have the truck and complete the job.