i am wondering if i can put a 1990 integra ls motor, which is a b18a1 into a 1988 honda crx

 

if you have a si crx it's a straight swap. if you have an hf, you'll need to get hubs/knuckles from a dx or si crx for the b series axles to fit. if you have an ef or dx, you'll need to wire it up for multi port fuel injection for it to work with the b18 motor since it has four injectors and the dx and ef only use two. crx's also use a resistor box for injectors so you will need some low impedence injectors. i'm not sure what kind the ls uses. hopefully you have a hf or si. it will make it a much easier swap for you.