there is a lot of heavy metal band in 70's some of it are King Diamond and Black Rose and Fallout that was just two of the many heavy metal band in 70's
Deep Purple, Led Zeppelin, Rush, Uriah Heep, Blue Cheer, UFO, Blue Öyster Cult, Focus, Slade, Head East, Aerosmith, Humble Pie, Zebra, Montrose, Pat Travers, Alice Cooper.
Manilla Road. Nektar. Samson. Brainticket. Hawkwind. Leaf Hound. Leige Lord. Riot. Uriah Heep. Saxon. Budgie. Icecross. Sir Lord Baltimore. Quartz. These bands do vary in heaviness but they are all semi to pretty heavy.
oh yea, i know then too. any other plz?