Ok so im new here and new to the honda game so I bought a b18c enigine and transmission and also a 99 honda civic ek shell I had a couple questins first off which engine harness would I use I was told a 99-00 honda civic si ewh would be it but im not sure and also which mounts and t bracket would I be using and which ecu should I run it on

 

You can use the 99-00 Si or Ex harness. You'll still have to make some wiring mods.

https://honda-tech.com/honda-civic-d...-vtec-2987229/

B-Series EK Engine Swap Guide | BC Garage

How To: B18c Swap Into A 6th Generation Civic - ClubCivic.com - Honda Civic Forum