So I reinstalled one of the fuel tanks, connected the new fuel lines of equal length from both tanks to the T valve and ran it to the "mechanical" fuel pump which now is not pumping fuel. Mind you this new fuel filter had water in it before I removed all of the fuel and cleaned the tanks. The odd thing is I ran the tanks separately and it pumped fine. Now with both hooked up there is no fuel flowing to the filter. 
Could it be this new fuel filter was damaged although I don't see how if I successfully ran both tanks separately and fuel flowed thru? 
I am able to keep the engine running as long as I keep the carb's float filled all the while no fuel is being drawn from the tanks.

My next step is to disconnect the high pressure line and see if there is blockage from the pump to the Quadrajet carb.
Any other suggestions?

GT,
I didn't prime it although that came to mind shortly after posting. What is the best way to prime, running fuel into the high pressure side?
also not sure what you mean by blowing backwards into the fuel pump. Isn't there a diaphragm which could rip?

i think glen meant to blow in your fuel line back to the tank to see if any blockage. what type of fuel filter do you have in line me  i useally pull the fuel line at the pump and apply air in the gas fill. just alittle air not much then wait for the fuel to come out then hook it up to the fuel pump good luck

Got it I'll try although there shouldn't be any blockage since I cleaned the tanks and the engine ran fine with the tanks hooked up individually. It does appear to be related to priming as Glen suggested. 

Did you put gas in the tanks?

[/b]

So I reinstalled one of the fuel tanks, connected the new fuel lines of equal length from both tanks to the T valve and ran it to the "mechanical" fuel pump which now is not pumping fuel. Mind you this new fuel filter had water in it before I removed all of the fuel and cleaned the tanks. The odd thing is I ran the tanks separately and it pumped fine. Now with both hooked up there is no fuel flowing to the filter. 
 

Are you referring to the brass type fuel selector valve or something else? Those brass valves are available in 2 configurations: 3-way and 4-way. The 3-way has "left", "right" and "both" settings. The 4-way has left, right, both and OFF. Is it possible you have the 4-way and have inadvertently set it to the "OFF" position? IIRC, the "both" tanks setting would be with the short end of the handle facing the outlet of valve.

Are you referring to the brass type fuel selector valve or something else? Those brass valves are available in 2 configurations: 3-way and 4-way. The 3-way has "left", "right" and "both" settings. The 4-way has left, right, both and OFF. Is it possible you have the 4-way and have inadvertently set it to the "OFF" position? IIRC, the "both" tanks setting would be with the short end of the handle facing the outlet of valve.

It's a brass 3-way T connection, no selection.

Could have some crap stuck in the valves of the pump.

Can you blow backward into the fuel line? That is a pretty funny test but will tell you if both valves are stuck open...

Did you prime the fuel filter?

Mechanical pumps can take forever and a day to start pumping fuel if totally dry..

GT

It's been a while since my last post about this but I finally got around to priming the fuel pump and she started up although I could see lots of bad looking fuel running thru the filter and because there wasn't much fuel in both tanks I ran the engine until all of the fuel was consumed. I then filled both tanks with a few gallons of fresh fuel and she now runs beautifully. Thanks for everyone's help.