Deck Hatch Hinge Bolts

Does anyone know the correct size and thread - I can't seem to get any of my taps to fit

hatch1.webp
 
What year is the car? You got give us more info.
My mistake - the car is a 1986 Mustang GT hatchback - the replacement hactchback is fram a 1991 GT hatchback - I'd like to run a tap through the hindge threads - the size appears to be 1/4" both both fine and course threaded taps are not wanting to thread in by hand and I sure don't want to f it up by forcing it through.