although this is very late, you will find that you dont need a crazy extension if you took the airbox and intake hose off when i got my 97 Civic HX from a friend for 500 i got the head gasket replaced then it was discovered their was a leak in the water pipe that ran across the back of the block from the thermostat housing to the water pump and with the airbox off it was alot easier to work with..
and my civic i put Pulstar Iridum pulse plugs and filled it with 3.5qts of mobil 1 synthetic extended performance and a K&N performance filter(Would of stuck with matching Mobil1 Filter but it was rusted from moisture caused by water leaking into trunk from welds near the trunk gasket.) so other than all that and needing a new o2 sensor and possibly cleaning of the egr passageways i would probably nearly restore my 111k mile civic
