how hard is it to put a b18b in a 90 CRX DX. The b18b is OBD2 and my car is OBD1 so is it worth it for the newer engine with more horse and torque or should i get a b18a thats OBD1.

 

What year is you car? Did you convert it to obd1, if not it's obd0. The swap is not hard and you can get a harness made for all the wiring, see sig for the link.

Also try a search, this has been covered a bazillion times and there is tons of info on this.