engine number?? good luck on that not all ford motors have an engine serial number... somtimes you'll find one on the flat spot behind the intake manifold right where the bellhousing bolts up.... sometimes on the flat spot below the passenger side head on the front of the block... but most the time its actually a stamp from an engine builder for warranty ID purpose..... the DMV should not need that information to register an older vehicle... they should only be asking for the VIN #