os 9 on a summer 2001 imac

i have a os 9 cd, that i want to install on my 500 mhz summer 2001 imac. This was a mod that i did, so its the logic board from the imac and an atx conversion

right now i have a 80 gb HDD with panther installed, and it works perfectly

i want to intall os 9 on another hrd drive, and if i want be able to swap the 2,. so i need a fully bootable os9 HDD, not running classic under OSX

when i install from classic in osx to my new HD, it dosent boot from that HDD. what should i do?

thanks
eric