Yes, but it's not possible without doing a full tape backup & restore.

Any of the supertars can fdisk and reformat a hard drive during restore
so using one of those you can do a full master backup, with bit-level
verify enabled, then do another, and if both suceeded without error
then you can boot to the restore floppy, use the recovery software
advanced options to override the defaults and create one big fs (don't
forget to retain swap and recovery spaces though) and then restore onto
that, and /u will just be a directory after that.

I suggest doing the restore onto another disk rather than blowing away
the original disk however.
There is certainly a lot of ways to botch this and if you are asking
the question then you obviously do do this routinely, and so, better
restore onto a different disk so that you can always plug the original
disk back in and resume running on that no matter what happens.

supertars = backupedge / lonetar / ctar
install any of their demos if you don't have one of them already, then
buy it and instruct the customer to change tapes every day and take one
home every night.