I have a friend that did this. he had an older Civic SI. 89 I think. He pulled his stock head and used the newer vtec one. It pulls ok I guess. At first he had vtec running off a switch he had to turn on and off. it was hilarious.

He did all the work himself (he's leader of the schools motorsports team, just one first place in world competition). I dont think there is much to this head swap.