Well fist, what year civic are you talking about. Second you don't have to move the firewall at all. I just finished putting in a B18C1 (integra GSR) motor into my 97 Civic. It fit with no problem. If you have a 92-95 civic and want to put a b16a it will fit with no problem. Make sure you buy the whole swap ( motor, trany, ecu, axles,shift linkage, wire harness, eng. mounts etc.) If you have a 96-00 civic you will need a 99-00 civic si engine wire harness and the aft eng. mount bracket. Unless you want to do a lot of cutting, extednding and add wires and plugs to your oem civic harness. I was able to use my 97 civic eng. harness, but I had to do a lot of soldering. Its up to you how you want to do it. But make sure you get all your parts first before you attempt your swap. Im still looking for a GSR catalitic converter
. Good luck. :alien: