Your gap should be (Gap 0.044inch) for DOHC 2.5l Altima
0.044 is your spark plug gap.
Most all auto spark plugs that are sold today are already properly gapped for the auto they are going into. If you visit your local auto parts store, they can look up the plugs for your Nissan Altima and you won't have to gap the plugs yourself.
It is 1.0 mm to 1.1 mm or 0.039" to 0.043" You can check in the manual for Nissan 1997 Altima
The correct spark plug gap is .044
The gap should be 0.043 inch.
1.1mm or .043 in.