Although it bore an unlikely title (picked up from a radio talk show), "Life Is a Minestrone" (1975) was another UK Top 10 placing, peaking at No.7. Their biggest success came with the dreamy "I'm Not in Love", which gave the band their second UK No. 1 in June 1975. The song provided them with their first US chart success when the song reached No. 2. A collaborative effort built around a title by Stewart, "I'm Not in Love" is notable for its innovative production, especially its richly overdubbed choral backing. Godley stated:
10cc would also do some production work for Justin Hayward during this time on his single "Blue Guitar" for his "Blue Jays" project with John Lodge.
10cc's fourth LP, How Dare You! (1976), featuring another Hipgnosis cover, furnished two more UK Top Ten hits—the witty "Art for Art's Sake" (No.5 in January 1976) and "I'm Mandy, Fly Me" (No.6, April 1976). But by this time the once close personal and working relationships between the four members had begun to fray, and it was the last album with the original line-up.
10cc's success prompted the 1976 re-release of the Hotlegs album under the new title You Didn't Like It Because You Didn't Think of It with two additional tracks. The title track was the epic B-side of "Neanderthal Man", a section of which had been reworked as "Fresh Air for My Mama" on the 10cc album.