Straight forward swap. Use the D15b7 engine harness fuel injectors, mounts brackets, and transmission on the D16a6. You can run either the B7 or A6 intake manifold but I would run the B7 throttle body. Obd0-1 is just the on board diaagnostics and all computer related. I cannot emphazize enough that Obd whatever doesnt make the engine what it is, meaning any 88-00 Honda sohc D series can be put in any 88-00 Civic chassis. Its the year of the car that determines the amount of work to be done.
88-91 Civic/Crx all Dseries are simple to swap Obd0 engine harness/injectors
92-95 Civic all Dseries are simple to swap Obd1 engine harness/injectors
96-00 Civic are a little more complex since Honda started putting the Crankshaft sensor on the block instead of the distributor. This means in order to put a 88-95 Dseries into a 96-00 chassis youll need swap the older oil pump for a Y7/Y8 one. Then youll have the proper spot to mount the CKP sensor on the engine. Like above you want to use the engine harness/injectors from the 96-00 as well.