ZC engines sit around and a lot of their parts get damaged and they are all like 11 years old at least. Plus they are a bastard engine and knowing which parts fit on it can be difficult. A SOHC VTEC engine could come out of a 2000 Civic and only be 2 years old. Plus as these engines come in USDM cars you could get a cheap SOHC VTEC Engine if someone with a 92-95 Si/EX or 96-00 EX were getting a B-series swap.