Posted for "Christopher Skelt" <cskelt@earthlink.net>:

 
 Randy,
 I decided to install a 3-way valve (Andair) to pull fuel from left, right or
header tank, some years after closing out the wings of my 320 with no slosh
boxes. The principal reason was to avoid a situation where an electrical
failure left me with 40 gallons of unusable fuel in the wings and an empty
header tank. This was before I heard about wobble pumps that are good in
emergency. Fortunately I had already plumbed from the wings with 3/8 tubing,
 not the 1/4 called for by the manual, so the plumbing modification was quite
easy. An EAA technical counselor told me that it should be OK, but to plan to
take off and land using fuel from the header tank that has slosh doors. So no
practical experience, nor a certificate of airworthiness, but at least
positive advice from a wise source.
 
 You could unport the fuel but the head between the pump on the firewall and
the port on the tank is less than a foot, so your pump needs to suck less than
0.4 psi to re-establish flow with an almost empty tank. Whether that will be
work in the TX midsummer or result in unrecoverable vapor lock I don't know.
 
 Regards, Chris.