There's a limit imposed on drive size, but it's exclusively a result of the operating system rather than any inherent hardware limitations of the Macintosh. System 6 and 7 up to 7.5 only support partitions up to 2 GB, but will support a drive larger than 2 GB if partitioned into 2 GB sections. However, Apple's drive partitioning tools only support eight partitions per drive, so you're still looking at only 16 GB accessible.
System 7.5 increased the max size of a partition to 4 GB. System 7.5.2 later increased the maximum size to 2 TB, but only on Macs with built-in PCI slots, which would not include your Quadra.
Mac OS 8.1, which introduced HFS+ formatting, allows addressing up to 2 TB of drive space, however, 68k Macs (including your Quadra) cannot use a drive formatted as HFS+ as a boot drive. If you're interested in that kind of setup (say for a server or something), it's easy enough to partition a large drive with a <2 GB HFS-formatted boot partition, and then format the rest of it as an HFS+ data partition.
Certainly if you want to try it, though, the Mac should work with the 120 GB drive, albeit addressing only 2 GB.
Do you mean that the weird jumperless drive mounts on the Quadra? If so, that means your IDE bus and cables are probably good, which is good news. If not, I'm not sure what sort of drive you're describing, and I'm not sure if it will work in the Mac. But the 120 GB is worth trying to make sure everything works in the machine.
If you're using the original CD, you are probably using the "Internal HD Format" application. That's what I remember the formatting utility released with the initial IDE-based Macintoshes. As I posted on another thread, this utility is incompatible with certain drives (particularly newer ones, but perhaps also non-Apple-ROMed drives, as in your case) because it does not recognize the partitioning information the drives leave the factory with. It seems a strong possibility that you having formatted the drive in a newer machine included the partitioning information on the drive, which the Quadra's drive setup utility is unable to recognize.
Do you have a newer system software CD? I'd try booting the Quadra up with an 8.0 CD and formatting the drive there, using Drive Setup 1.0.3 or higher.
(The Quadra doesn't have a PowerPC upgrade card does it? That will cause problems with older versions of Drive Setup/Internal HD Format.)
System 7.5 increased the max size of a partition to 4 GB. System 7.5.2 later increased the maximum size to 2 TB, but only on Macs with built-in PCI slots, which would not include your Quadra.
Mac OS 8.1, which introduced HFS+ formatting, allows addressing up to 2 TB of drive space, however, 68k Macs (including your Quadra) cannot use a drive formatted as HFS+ as a boot drive. If you're interested in that kind of setup (say for a server or something), it's easy enough to partition a large drive with a <2 GB HFS-formatted boot partition, and then format the rest of it as an HFS+ data partition.
Certainly if you want to try it, though, the Mac should work with the 120 GB drive, albeit addressing only 2 GB.
Do you mean that the weird jumperless drive mounts on the Quadra? If so, that means your IDE bus and cables are probably good, which is good news. If not, I'm not sure what sort of drive you're describing, and I'm not sure if it will work in the Mac. But the 120 GB is worth trying to make sure everything works in the machine.
If you're using the original CD, you are probably using the "Internal HD Format" application. That's what I remember the formatting utility released with the initial IDE-based Macintoshes. As I posted on another thread, this utility is incompatible with certain drives (particularly newer ones, but perhaps also non-Apple-ROMed drives, as in your case) because it does not recognize the partitioning information the drives leave the factory with. It seems a strong possibility that you having formatted the drive in a newer machine included the partitioning information on the drive, which the Quadra's drive setup utility is unable to recognize.
Do you have a newer system software CD? I'd try booting the Quadra up with an 8.0 CD and formatting the drive there, using Drive Setup 1.0.3 or higher.
(The Quadra doesn't have a PowerPC upgrade card does it? That will cause problems with older versions of Drive Setup/Internal HD Format.)