Lone Rager's "Metal Rap" EP out of 1984 on Megaforce Records.
Megaforce is a record label run by Jon & Marsha Zazula, formed early after Jon opened a record shop in New Jersey called Rock 'N Roll Heaven (legend has it that he was originally going to name it "Metallica Records", but a certain Lars Ulrich convinced him otherwise, calling it stupid, and then copped the title for his recently-formed band) after getting Metallica's demo in the mail & deciding he wanted to release their first album.
And this here Metal Rap release is Jon's loving ode to the genre he still promotes to this day. Now, there's no official evidence that the "Lone Rager" IS Jon Z, but as the back cover states: music & lyrics - Jon Zazula, Producer - Jon Zazula. So I think it's safe to say that the hefty boy on the front sweating through the pillowcase is Jon Zazula.
The music? Aheh. Um, well, it's exactly what it says it is. Doesn't get much more earnest than this. This is love, baby, love for metal. And if you hear tiny voices in the chorus it's not your ears ringing from the banging of the head, it's The Children of Steel Singers - a chorus of 15 kids aged 3 months (!) to 10 years old, including a Rikki Zazula.
The first side is the rap, the second side is the same tune minus the vocals which are replaced by a blistering (?) mass of guitar-soloing by Andy "Duck" MacDonald and they both clock in at 5:26.
And, in case you're too busy swingin' that hair around (or laughing) to listen properly, here's the lyrics from the rear cover, clickable for readability -