its illegal, you get 7 points pretty much instant loss of licence, there are cops that know their shit, some don't i woulnt risk it though.
b18 is ok in a civic because its 1.6l > 1.8l conversion, which still fits under the rules.
1.6 > 2.4 is over the 15% increase

2k for a k24? with all the gear to get in running in an ej? cos i know k24 blocks are only 1k at jdmyard and its another minimum 9k to get it in and running.