This might not really answer your question, but there's an option you
can use to switch from one grub to another (in stage 2).
When I was switching from FC6 to F8, I installed F8 on a separate
partition (not wishing to destroy any of the old data). That included a
fresh /boot partition.
Then, I added an entry to the new /boot/grub/menu.lst:
title Fedora FC6
root (hd0,5)
configfile /boot/grub/menu.lst
(hd0,5) was the old / partition
Since I initially installed grub to MBR, instead of partition,
chainloader directive didn't work
HTH
