fuel rail plug size

[Cratos]

anyone know the tread size for the o-ring plugs in the back of the head on a 7.3?

[Clay Henry]

cant remember for sure but i want to say 1/4 thread....but actually that sounds too small...maybe 3/8"?
Pull the front banjo fuel bolt and see. It will be the same.

[Cratos]

the one in the back of the fuel rail that seals in th ends of the fuel rails with the 1/4 square drive loos like treads are 7/16 or metric

[Clay Henry]

might be different than a 6.0?

[Cratos]

7.3 12 mm x 1.75

[Marty]

Yes, different then a 6.0.