“Those who, through no fault of their own, do not know the Gospel of Christ or his Church, but who nevertheless seek God with a sincere heart and moved by grace, try in their actions to do his will as they know it through the dictates of their conscience—those too may achieve eternal salvation.”

Lumen Gentium §16

…those men cannot be saved, who though aware that God, through Jesus Christ founded the Church as something necessary, still do not wish to enter into it, or to persevere in it. Therefore though God in ways known to Himself can lead those inculpably ignorant of the Gospel to find that faith without which it is impossible to please Him (Heb. 11:6), yet a necessity lies upon the Church (1 Cor. 9:16), and at the same time a sacred duty, to preach the Gospel.” 

Ad Gentes §7

Logically the group described in the quotation from Lumen Gentium §16 ought to be “those inculpably ignorant of the Gospel”. If they need to be led to “that faith without which it is impossible to please Him” then they do not have it already. Thus they are not justified. Implicit faith is not mentioned. It is already solemnly defined by the Council of Florence that “except a man believe the Catholic faith truly and firmly, he cannot be saved.” Thus, whatever the ways known to God Himself may be they do not include non-explicit faith.

In the words of St Fulgentius, “He willed to be saved those to whom he gave to know the mystery of salvation; those to whom he has denied the knowledge of the mystery of salvation he does not will to be saved” (De Veritate 3:18).