My 1989 honda civic dx is obd0 and the b20b that I want to swap in is obd2 how would I do the wiring for this swap, would it just be like a normal dpfi to mpfi conversion or would I have to covert the engine to obd1 to make it work.

 

The only issues you’d really have is getting acc power to the car, you may have to splice or find adapters to fit lighting and interior power. Although I’ve never done a swap like this it would be relatively easy as long as you have all the electronics to go with the engine.
you may have to find an alternate spot for the ECU as well, I almost guarantee the mounting points for the car are different than the ECU. Engine mounts may also be different, as well as CV shaft length, someone with more knowledge than me may be able to clarify, I’m far from a service expert, but these are my ideas.
im doing the same thing but putting an OBD1 engine in a OBD0 car, and these are some things I was worried about, but so far so good, I wish the same luck to you!