Where is the oil sending unit on a 1998 dodge 318?

The oil pressure sending unit on a 1998 Dodge 318 engine is located on the passenger side (right side) of the engine block, near the front. It's a relatively small, usually one-wire, unit screwed into the block. It's often near the distributor, but not always directly adjacent. You'll likely need to look closely at the engine block in that general area to locate it. A shop manual or a diagram specific to your 1998 Dodge 318 will provide the most precise location.