I have a 1990 Honda CRX DX that my sister bought brand new in 1990. I've been bugging her for years about when she would get rid of it and give it to me and finally, two years ago, she did. It's been sitting in my garage ever since (unregistered and won't pass emissions). Without going into too much detail, I've finally got the time and proper tools to do what needs to be done to get it to pass emissions and run properly (new cylinder head). I got a factory service manual for 88-91 that includes the "1990 supplement". Before I get in to the problem, know that she had a problem about 4-5 years ago (I think it was that her timing belt snapped, but I can't remember for sure), that resulted in her getting a whole new engine...the shop she took it to could get her another one for around $800 including labor. A guy I worked with had a cylinder head from a D15B2 that was in really good shape so he gave it to me. So I went to check the code on the engine and it is a D15B2. So when I went to start studying the service manual I looked at the engines that came in 1990 CRX's and the D15B2 wasn't one of them. I looked at the VIN code to determine what originally came in the car and the part that designates the engine says (ED8) which the service manual (the 1990 supplement) doesn't list as an option for that car. Bottom line, I know my engine and the new cylinder head are D15B2, but I want to see if there is something I am missing. I try to do everything by the book, so to speak, so if there is a difference in engine I want to make sure I pull the motor and replace the head according to the proper guidelines... i.e. the correct service manual. For the record, I am planning on getting a B series in the next six months or so but in the meantime I would like to cut my fuel costs since I have a crappy commute (compared to my WRX) and the reason I am pulling the whole motor to change the head is for experience and to clean things up a bit. I didn't want anyone thinking I was going to let this CRX go to waste by keeping the craptastic stock D Series .

 

If the CRX is a DX model, it shoould have a d15b2...if its an Si, d16a6

 

You can put ANY D series single cam head on that motor.

You can even put a vtec head on it.

But the direct swap with no problems or extras will be the B2 or A6 head.