Can you swap out a 1998 Acura Integra gs-r vtec engine with a 1998 Acura Integra gs engine?

ya for sure, any B18 engine can fit in an integra. I don't know why you would want to swap in a slower engine tho...

The GSR engine is a B18c which comes with VTEC pulling out about 178 hp @ 7600 rpm and a GS/LS/RS usually come with a B18b Non VTEC pulling out about 142 hp @ 6300 rpm.