well what yr and model civic do you have? when you pop the hood does the valve cover have an insert that covers the plug wires down the middle and wide or narrow and just rolled over w/ the 4 plug wires right there on top exposed?
easiest if you look at the motor and on the Engine block to the left of your headers you will find a # code like D15,D16 meaning a SOHC or if it has a B16,B18 etc it would be a DOHC and you will notice 2 cam sprockets to the right of the motor and not just 1...
SOHC
DOHC
Hope this is of some help to you...