any engine swap puts you into SM(Street Modified), or a SP(Street prepaired) class

with a non-US engine, or a engine that did not come in that cars trim level puts the car into SM. Meaning that a DX with (US)SI engine is a Steet prepaired class. Most hondas go into CSP.

With a jdm engine or engine out of a nother line, Accord, integra, CRV puts you into SM.

Thats the basics for engine swaps hope this helps.