upgrading 7.2+rawhide -> rh8.0 via grab

Hi there,
I have the RH8.0 RPMS stored on a local disk, and want to upgrade my
current system (which is a mishmash of 7.2, rawhide, and external rpms) to
rh8.0 via grab (I'd like to avoid any downtime).  Ran 
./grab-devel --buildrep on the rh80 dir, and that went fine.  Then did a 
./grab-devel --autoupdate -t 
and that seemed like it was going fine, until the rpm -Uvh --test phase (on
551 packages), which exited with many dependency messages (~40).  Is it not
possible to have grab examine these dependency messages and add the
necessary rpms to the list, and re-run rpm -Uvh --test?

Has anyone done this migration yet?  Any words of advice?

Cheers,
-- 
  Ami Fischman
  [email protected]