If you have pre-DR3 (which was frozen as the final DR3 in late May of 1998) 
of Mklinux installed, you can easily upgrade to running LinuxPmac on a PCI
PowerMac. Some simple steps are...

1) Install the following rpms from /RedHat/RPMS on ftp.linuxppc.org...

quik-1.3.0-1.ppc.rpm 
pmac-utils-1.1.1-1.ppc.rpm 
kernel-headers-2.1.24-1.ppc.rpm
kernel-pmac-2.1.24-2.ppc.rpm
kernel-pmac-modules-2.1.24-9807

(note that you will have to use 'rpm --force -Uvh' to install the pmac-utils rpm
since it provides /sbin/clock as does Mklinux's clock-mklinux rpm.

2) as root execute...

quik -v

3) reboot follow the normal linuxpmac installation instructions for setting up
the OF boot variables. Also you should read the faq entry on booting Linuxpmac
on the G3
if you have one of those.