Awesome thsinks very helpfukit's an Inline 4/straight 4 with you want to call it. If it were a V it would have 2 cylinders on each side with 2 cylinder heads not one like yours has. What you may be getting confused with is that 91-93 mustang (and California 90) have 8 spark plugs instead of 4, the look may be a little deceiving but it still only has one cylinder head.