Yes, it's 4GB, but the boot partition has to be entirely within the first 2 Gigs IIRC if you're not to have problems, as it must be able to read it with the filesystem in the Kickstart ROMs before any updates or patches are installed. However, If you're still using KS1.3 you'll have problems with partitions that size anyway, OFS has a much smaller limit (of the order of <1GB) so you may want to look at upgrading to a 1200 or upgrading your kickstart.
