.035 inch , according to motorcraft.com , one of Fords websites
( .035 inch ) is the spark plug gap
Ford uses Motorcraft Spark plugs on all there vehicles.
.035 inch ( for the 302 / 360 / 390 cubic inch V8 engines )
A 1968 Ford Galaxie 500 with a 390 engine should use a spark plug such as an E3 brand spark plug. This plug should have a tapered seat with 18mm threads.
fordparts.com shows the 1967 Ford Mustang 390 cubic inch ( 6.4 liter ) spark plug gap as ( .035 inch )
.035 inch spark plug gap for a 390 V8 in a 1973 Ford truck ( according to www . motorcraft . com - no spaces )
.044 inch
When changing spark plugs on a car, it is important to have a diagram. For a 1969 Ford 390 V8, a person can find a spark plug diagram in the maintenance manual of the car.
I've seen 360, 390 and 460 all said to be standard.
Points .017 and spark plug .035
bad
It will serve the purpose and may fit perfectly or you may have to do a little modification.