yes there is a screen on the sending unit and like I said before its brand new. I just successfully drained all the gas out of the tank using the new fuel pump with no issues so that means the 9 or 10 gallons tempted hat was in the tank got emptied with no ventilation problems at all. seems like there's some sort of problem only when gas is sloshing around and blocking some sort of venting. I also just noticed that my brand new fuel inlet hose is kinked. No I don't know if its kinked all the way to the point where its not letting the gas cap vent but I'll try to take a picture and post it for you guys.

Maybe you need a pressure regulator on the pump? Here is a little copy and past info for you.

Ford 351M and 400 fuel pumps put out about 7 psi if "spot on".

Holley and Motorcraft Carbs can take in excess of 7 psi due to longer float arms with large floats. Carter AFB & AVS & Edelbrock carbs have shorter float arms which is in part why they are more compact, and smaller floats and they are less tolerant of higher fuel pressures, 6 psi is the max that Edelbrock recommends for their carbs which are copies of the Carter carbs. They recommend that a max pressure used at 5.5 psi. High fuel pressure does not mean more power as many cars we considered as muscle cars used 4-6 psi.

You likely need a decent Fuel Pressure Regulator like Holley's # 12-803 and use a fuel pressure tester in a tee between the carb and FPR to set pressure at 5.5 max. Do not waste money on a Spectre or Mr Gasket FPR. Once set you can remove the tee and tester.

If you can fill the tank with no problems, she'll breathe fine....doesn't the tank have a breather alongside the filler tube?

Also, have you checked the line from the (mechanical) fuel pump to the carb for problems/tightness?

well guys I double checked everything I dropped the tank checked the sending unit filter and it was fine. Made sure all my lines were tight. The only thing I can think of is that I had 2 faulty pumps and the electric gravity feed pump that I put on only went bad because of the area I have it mounted. After doing some research gravity feed pumps supposedly need to be mounted next to the gas tank, I have this one mounted like I've had others mounted on Mustangs in the engine bay. I've never had a problem in the past with the mounting location but maybe just maybe this is why the electrical one went bad. I might just take this second electrical pump back and try a third mechanical. I've gotten two pumps from Napa and I don't really like the mechanical pumps with the built in filter. Does anyone know of a parts store that has a pump without the filter canister attached? It's just so huge and I don't like it I would rather just have my own filters.

PM ND Bill. He can get ya the part number of the pump without the filter housing
if available.

You was asked at one point if ya had spark when it quit on ya. Did ya ever check?
It could well be a weak coil or condenser Bud. Same symptoms pretty much.
A weak coil will run about 5 or 10 minutes until it gets hot. Than quit until it cools down and work again. Same with the control Modual if ya have one.

I've killed multiple electric pumps when I had them pulling more than pushing. Also run a 10 gauge wire for the power, and make the ground wire as short as possible. Strain through a wire that is too small will kill any electric motor in a hurry.

spark is not the issue

I second the fuel pump pressure regulator. Probably not the cause of this problem but if its putting out more than 7 psi, you will have more problems later on.

So ya are positive spark is not an issue and we can move on?
Please tell us how ya determined this.;)

Because I can hook an electronic fuel pump to the hot motor and it starts right up. Also pouring gas in the carb starts it right up. Before changing my fuel system the truck ran fine. I'm 100% it's not a spark issue.

Bud I am just sayin that if it sat an cooled down for as little as ten minutes a bad coil could restart it. To eliminate that would be to see if ya have good spark when it stalls. Immediately. Or if at the stalling point if ya pour gas in the carb will it fire?
A simple thing. I do agree it's prolly a fuel thing. But?

Sorry I am old school and prolly a bit slow. Just trying to help.
Please don't flame me to bad. I get enough of that at home.
But ya seem a bit stubborn Bud. As am I. Sorry. Carry on Mates. :-jammin
It's all good. Just that some is better than others.:-X04

Can you let it sit in the yard and get it to stall out ? Or do you have to actually drive it ? If it will do it at home you can do better testing while comfortable in your surroundings . Is the needle or float sticking closed . Fuel line too close to heat and vapor locking , soft line sucking closed , trash stopping op fuel pick up and falling away after sitting ... Just a few thoughts .

I know your trying to help. And thanks for your advice. I ordered a airtrex fuel pump and it gets here in 2 days so I'm gonna try that and we will see.

Best of luck , let us know how it turns out !