Hey there and welcome to PCHF,
If you're sure the new HD has an SCSI interface, you'll need to get an SCSI card for it such as:
Newegg.com - StarTech PCISCSIUW PCI SCSI Ultra Wide Card - Retail
I've never really dealt with SCSI drives, but I'm fairly sure you'd need one of those type of controller cards as I don't ever remember seeing a motherboard with an SCSI interface port of any type. SCSI controllers are very expensive btw, as most SCSI drives tend to be extreme performance server-scale drives. They're not meant for everyday usage, not the current new SCSI drives anyways