What is your fastest time to pull an engine, install another and drive it away?

2 days, but I was swapping out a 250 straight 6 and 3 on the tree out of a 71 Chevy C/10 and installing a 350 I rebuilt along with a Muncie M-21 4 speed. The motor and trans bellhousing mounts are in a different location for the V8. Required me to grind and punch out rivets to remove the straight 6 crossmember that mounts the bellhousing , then install the V8 one in the right spot. Plus reconfigure other stuff to make it all work. If it was a straight R&R same type out and in it would be an afternoon. Idrove to work that monday morning with headers and glass pack header mufflers. That truck along with my 69 charger were 2 vehicles I should have never let go of. If this truck already had a V8 in it. The swap would have taken maybe 4-6 hours tops.