what cpu type to use for a intel duo e6850 (i386 or amd64)

[Aryeh Friedman]

Would the following procedure work to do an inplace upgrade:

1. Download the amd64 iso
2. Install it on a spare disk/partition
3. Do a cvsup on it's /usr/src
4. Make buildworld/buildkernel
5. Mount the x86 disk/partition
6. Copy /usr/obj (and /usr/src for good measure) from the amd
partition to the x48
7. Reboot with x86 partition
8. Make installkernel/installworld mergemaster on x86 partition
9. Now the non-ports section OS is amd64
10. pkg_del /var/db/pkg/*; rm -rf /usr/ports/ /usr/local
11. Reftp ports.tar.gz and rebuild all the ports (I have about 10 top
level ports installed the rest are dependicies so this straight
forward)

So does it work?