Ford LTDwith 400m cuts out?

Fuel filter or fuel pump problem or it could be the automatic choke is closed and choking motor make sure choke is plugged in on side of carb start car let it warm up with air breather off watch and see if choke opens up .also you can look down into carb when motoe running crack open throttle and see if it sprays gas into intake if it doesnt could be filter or pump. to check fuel pump remove fuel line from carb insert line into small can or bottle so fuel doesnt run ontop of motor and have someone just bump over starter and see if it pushes fuel out line with a descent amount of pressure check fuel filter.and if all that checks out try looking for vaccum line off to check get a can of either and squirt lightly around vaccum lines and listen for car to idle up if it does bad vaccum line. and also check distributer. but it sounds like it is getting to much gas so i would check choke first..... hope that helps .. and by the way you have a 351 modified 400 wich is 351 m 400.