Won't idle (or run) unless almost fully choked

I have a 1968 Ford Mustang with a 302 from a 1979 Mustang. It has an Edelbrock Performer 1405 Carb and it was running great. Until I left it sitting for over 3 years. Then, of course, when I got it out to work on it, the gas had gummed up the carb. I tore the carb down, cleaned it out and replaced all the gaskets. Then it would not run unless the choke was almost completely closed (about a 3/16 inch opening). If you open or close it any, it will sputter and die. If you rev the engine and the airflow opens the choke, it dies. I thought maybe there was still a passageway or two still clogged so I soked the carb in a carb/parts cleaner. Trust me, it's definately clean now, but still the same issue. The idle mixture screws do nothing. You can open them all the way or close them tight with no noticable difference. Other useful information ... new fuel tank, new fuel pump, new fuel filter, all new rubber lines. The only thing left that is old is the metal line along the chassis. I am totally stuck, please help.