07 tahoe engine replacement help

[Mike_The_Grad]

Hey everyone I am currently in the middle of pulling a bad engine and replacing it with a reman engine on my buddys 2007 chevy tahoe with 5.3.
I already have it to the point where I am pulling the engine out in about an hour. The reman engine showed up yesterday. Everything matches up part number wise. My question is because this is my first ls replacement/swap. What needs or should be replaced while we are in the middle of this operation? His radiator leaks so that will be replaced. I know we should replace thermostat. His old engine has 200,000+ miles on it. What else and how to go about replacing it. Like sensors, crank position, oil pressure, temp sensors, etc. Is there a special way it was yo be done or can they just be pulled and cleaned up and put into the new engine? Or do they need to be in a certain orientation in order for them to come out, etc. I already know about priming the engine before we start it with oil. I have a pressure tank already yo go with correct fittings.
For sure I'm telling him that belts, spark plugs, thermostat, has to be replaced. What else? I'm going to continue researching online in the mean time and it will be at least 2 days before the engine goes in the truck. I will check back in mostly in the evenings and mornings to look for any help. Thanks you guys.