Sorry for the thread necromancy, but this is the only discussion I've seen where someone reported success with gparted.
Floofies, or anyone else:
Did you actually have success using gparted to resize HFS partitions on a 68k Mac? Firstly, linux live cds for 68k Macs appear not to exist. All installation methods both for linux and netbsd involve a bootloader launched from Mac OS (Penguin or similar). Secondly, there's not a modern distro that support 68k - Debian "revived" its 68k port in 2012, but the last official releases are from 2009. This is not going to have a recent version of (g)parted. GParted live cds are for x86(-64) only. Finally, people have reported issues with the apple partition map after using gparted to resize (report was on ppc).
I, and I'm sure others who will come across this later, need to know whether a) you have successfully done this and, if so, with what "live cd" or b) you were speaking in theory (it ought to be possible), or confused the case of doing it on a modern x86-64 "Mac" with doing it on a 68k classic Mac.
Cheers,
-p