B-series into a 3G civic frame IS something major and requires all the wiring updates that a 16v D-series head swap would need. The good thing is, HASport makes a harness for the job. B-series into this chassis is also a bit more difficult and a lot more expensive then doing it into a newer chassis... the mount kit alone is around $650. You still need custom axles, shift linkage, etc. Much money involved.