I have an AthlonXP box running the 2004.3 base system and a 2.4.22 kernel. It was built with:
CFLAGS="-march=athlon-xp -O3 -pipe -fomit-frame-pointer"

I would like to upgrade to an Athlon64 cpu and run the whole system at 32-bit. Just want a hardware upgrade, faster cpu, fsb, etc. No 64-bit stuff ...