Just thought I would throw some info in here for the next guy looking for the proper fuel selector valve. I my self have been looking for a selector valve to handle the higher pressure of fuel injection. After finding this thread and reading and doing a little research of my own this is what I found. I'm the type of person that wants to see it in black and white from the manufacture of the maximum allowable fuel pressure. For the Pollack valve part number Bulk-42-159 it was stated 65psi. Here is a link to where I found the information.
http://products.pollakaftermarket.co...S_41-revdd.pdf
For the A/C Delco U7001 valve I was able to find the information right from Auto Zone's web site by looking up the part number.
http://www.autozone.com/fuel-deliver...?checkfit=true
Hope this information helps the next person looking for it.