It should work assuming that a 4 gig drive is what you've got. If you've got a drive that is much larger, you may have to consider the other option.
The other option is to upgrade to a Kickstart 3.1 ROM (simililar in concept to the BIOS on a PC) and install a 64-bit filesystem (such as the ones included with AmigaOS 3.5 and 3.9) on the second partition and keep the first partition small so the Kickstart will recognize it at boot time.