Civic EG

Well basicly i was wondering if it would be possible to use my stock b7 intake manifold with a y8 head ,also would doing so cause any loss of power?

Yes it is possible to do, and you will gain power from the vtec.head swap but for optimum performance you woukd want the y8 intake manifold as it is factory tunned for that y8 head

exactly what forcefedEG said. Same goes for all Honda heads, they usually achieve best results when matched with the intake that Honda designed for them