According to one of Fords websites :
For a 1990 E-250 Econoline :
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The 4.9 liter / 300 cubic inch inline six cylinder engine and the 5.8 liter / 351
cubic inch V8 engine have the spark plugs gapped at ( .044 inch )
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The 5.0 liter / 302 cubic inch V8 engine has the spark plugs gapped at
( .054 inch )
gap is 42
5.4 eng spark plug setting is .052-.056
On the distributor cap
Check your underhood sticker, it should say.
.042 to .046 inch
Check VECI label under hood!
( .044 inch ) according to fordparts.com
spark plug gap on 1990 ford ranger 4.0?
I believe they sit on top of each spark plug.
.044 inch
My Chilton book shows ( .040 inch ) spark plug gap for a 1990 Ford Festiva 1.3 liter / 81 cubic inch 4 cylinder engine
The recommended spark plug gap is .044"