According to the Hanes Manual: .044
.044 inch ( for your 4.9 liter / 300 cubic inch straight 6 cylinder engine in a 1991 Ford truck , according to motorcraft.com )
The spark plug gap for 1987-1991 Toyota Camry: 2.0L, 4-Cylinder is 0.044.
Check the spark plug and the wire on the 8th spark cylinder. Corosion, short, or just bad.
passenger side of engine , front cylinder
1991 Jeep Cherokee 2WD 4.0L MFI 6cylThe Spark Plug Gap.035 (In thousandths of an inch)
The diagram.
.035 inch
The spark plug gap is .054"
The spark plug gap is .054"
www.motorcraft.com shows (.044 inch ) plug gap on the 1989 F150 300 cubic inch ( 4.9 L ) straight 6 cylinder engine
I think it's .035