Found the passage in SHEAF, HEARSE, COFFIN, POETRY NOW: A HISTORY (Hearse Press, 1996) on page 23:
"I let HEARSE lapse in 1961, because of other obligations. In 1969, two things happened which brought me back to publishing again. In culling some old files, I found a hefty envelope of unpublished Charles Bukowski poems, which Bukowski had apparently sent me some time previously (the postmark-date was not readable), but which I had filed away and forgotten. Among these manuscripts was the long poem 'The Days Run Away Like Wild Horses Over the Hills'. I wrote Bukowski, asking if this poem was still available, and saying that reading the poem made me itch to start publishing again. He replied that the poem was still unpublished, and that if I wanted it for HEARSE, I could have it." -- E.V. Griffith