SCSI hard drives

I have a Compaq Proliant 1600 NT4 Server that does not have a RAID controller in it. When it was originally set up someone put the two hard drives in bays 4 and 5. I am wanting to put those in bays 1 and 2 and then fill up the other three bays with more hdds for extra storage. These are the Ultra Wide SCSI hard drives. I am somewhat familiar with SCSI IDs. I know they start at 0, etc, but I’m not sure if I am going to run into any problems when I switch these out. Does anyone forsee any problems that I may run into? Thanks