I ended up buying the 158 like you suggested. Just replaced it, bled the fuel system and did the t-valve test again like you described. Last time it ran for 11 seconds and then died, this time it ran f or 22 seconds before it died. Still no fuel came out of the T-valve though. Next step will be dropping the tank and replacing the 'sock'.The AC/Delco EP 158 is the lift pump of choice if you can find one in your area.
It has a slightly better fuel flow as reported here in the forum