replacing center column on tiltall tripod with ball head

now that i've removed the center column of my 7lb tiltall tripod i am left with a 5lb tripod. the purpose is to replace the current 2 handle head with a ball head and try to make it a little lighter. not sure about the lightness objective since the head i am looking at weighs 1lb, the bogen 486rc2.

just called b&h asking whether they sold a connecting lightweight shaft to attach a ball head and they said no.

the hole left by the center column is 1 1/2".

anyone out there ever successfully do this and any suggestions for a lighter head?

thanks