32 bit to 64 bit

[Tim Kellers]

I'm upgrading a 7.3 -STABLE installation to 8.x, then 9- Stable over the 
next few days.  The hardware is a Dell 2950 that is capable of running 
64 bit FreeBSD.  The original installation was i386 32 bit and that is 
what it is running now.

Will the buildworld ---> buildkernel KERNCONF=FOO64 allow a 32 bit 
installation to build a 64 bit kernel?  I'd like to upgrade this machine 
to 64 bit AMD and I'd prefer not to do it from a DVD if I can do it from 
source.   Has anyone tried this and succeeded (or failed spectacularly) 
on a remote install/upgrade?

Tim Kellers