Oh yeahhhh. Alright, the eighth is in Viridian City, Giovanni was overthrown, so now Gary's the gmy leader. Man, it's been soo long since Crystal, and awhile since I got past this on Heart Gold.
I believe you have to beat the Power Plant sidequest, and then you have to go to the Radio Tower that's in Lavender. I believe one of the people in the bottom right corner give it to you.
Alright, after that, go back to Vermillion City. You'll see that fat ugly Snorlax, but you don't have a Poke Flute! (Aww man, I wish Red would lend us one..) Okay, go to your PokeGear's Radio station and make sure it's in the middle. Slide it directly up and it will begin playing music. Talk to Snorlax and it will battle you. (55% chance it will have a Leftovers, so I might want to keep on trying if he has it).
Seventh is in Cinnibar Island, surf there from (color) Pallet(e) town and go down. When you get there, talk to Gary. Then go right and you'll fight Blaine in his little gym. Then, go back and talk to Gary once more (but make sure that you already beat Brock) and Gary will go back to his little gym.
Oh yeah, and make sure you use a Rock, electric, or ice type when you fight him. He sends out Pidgeot first.