the small print on the bill. who did your swap... reputable or questionable... do you know what and or where the motor came from? what does the "warranty" cover? motor swaps either go 2 ways... good or bad. you can probably expect to have a check engine light pop on occasionally. usually a bad sensor from the donor motor... as stated, check your oil and life fluids..listen for noises and feel for strange new vibrations.. watch your oil pressure and temp guages like a hawk for the first few trips. and do your own oil change after a few hundered miles so you can inspect the oil etc too. if it goes bad, chances are good it will happen, immediately or within the first couple hundred miles. after you get through that 'stage" with minimal or no problems.... more than likey youll be good. good luck.. hope it works out to the good for you.
ps check the A/C if your equipped, being winter and all... hate to not check it and it be in-op later.