out front vs ahead

out front is not an adjective while ahead is an adjective.

Word	Noun	Adjective	Verb	Adverb
out front	No	No	No	Yes
ahead	No	Yes	No	Yes

As adverbs, out front and ahead are synonyms defined as:

Other synonyms of out front include in the lead.

out front (adjective)	ahead (adjective)
	having the leading position or higher score in a contest

out front (adverb)	ahead (adverb)
leading or ahead in a competition	at or in the front
	ahead of time; in anticipation
	in a forward direction
	leading or ahead in a competition
	to a different or a more advanced time (meaning advanced either toward the present or toward the future)
	to a more advanced or advantageous position
	toward the future; forward in time