Yes the chassis code may matter (depending on what you're comparing).Just curious.. and asking a noob question but does the chassis that the header is for make any difference?? for instance, one for a kswapped CRX, will it fit in an EM2/ES1? Thanks..
For example: a header meant for a K20 swapped EG, will not work on a stock DC5/EP3. If you do a search for headers meant for that setup, you'll see the design is completely different (one looks like a "L" while the other might look more like a "~"
I'm not positive in you're example, but pretty positive a k swapped CRX header will not work on an EM2.