To start with, No two engines are alike.
Not unusual for different engines to run differently.
You have to realize you installed a used engine with 150k on it.
Unless you have complete service records on the vehicle it came from, no telling what it was subjected to or how well it was serviced over its life.
You could try a tune up on the engine if that wasn’t performed at the time of the swap.
Replace the air filter, clean the throttle body etc and see if that helps.