SCSI HARD DRIVE switch out QUESTION

If it's an OEM installation, your G4 has a 68-pin SCSI drive, and not an 80-pin SCA (SCSI) drive. If you purchased it secondhand, it could have either. Why don't you install a Parallel ATA (ATA-133) or Serial ATA (SATA-150) hard drive with the corresponding PCI controller card? You can get a lot more storage capacity for your money, than you can by going with an expensive SCSI drive. Check the weekly sale prices at your local electronics, computer, or office supply stores for bargains on hard drives. For a Mac-compatible PCI controller card, you'll probably have to purchase one from a dealer online. The lowest price for an ATA-133 controller card is consistently found here.