Engine Swap? If it is a GS, then it already comes with a b18, just its a b18b. The GS-R is a B18C1 DOHC Vtec. You are looking at about 2,500 to 3,000 for the motor + Labor for the swap. Mite as well spend an extra grand and get the GS-R if you are going to plan to swap anyways. Or a cheaper way is to do a b16 vtec head on your b18b if you got the gs.