Former Judas Priest guitarist K.K. Downing said that working on his upcoming memoir brought him “close to tears,” and noted that some of its revelations will surprise fans who think they know everything about the band’s history.The book, Heavy Duty: Days and Nights in Judas Priest, is set for publication on Sept. 20. Downing followed up the official announcement with a Facebook post. “It was with great surprise to me that I saw articles recently relating to my book, as work is still in progress finalizing everything,” he wrote. “The internet-led world we live in doesn’t make it easy to keep secrets! However, I was secretly desperate to tell you all about this book, as my life story is something that I am very proud of – even though I suspect that some of the details will surprise you, just as they did me as I lived through them.”Downing said that looking back at his life while preparing the book “often brought me close to tears, but has also made me laugh with the fondest memories,” he added. “It is true that I have made many friends along the way, but it is also true that I have made some enemies. But one thing is for sure: The music that has been everything to me has not only been my salvation, but has also brought me closer to the people of so many nations – and I can honestly say that I consider all of you to be my very dear friends.”The 320-page book will reportedly cover “complex personality conflicts, the business screw-ups, the acrimonious relationship with fellow heavy metal band Iron Maiden, as well as how Judas Priest found itself at the epicenter of a storm of parental outrage that targeted heavy metal in the ’80s.”Downing announced his departure from Judas Priest in 2011; he was replaced by Richie Faulkner. The band has a new album, Firepower, scheduled for release on March 9.