Edelbrock stumble off idle???

For starters make sure the carb is box stock. (Jets,Rods,Springs).
This will let you know exactly where you are starting.Generally these carbs work very well right out of the box,with only minor adjustments.The pump shot arm has 3 holes in it. Stock uses the middle hole. Use the hole farthest from the base,for a larger pump shot.
YouTube actually has a couple really good videos on initial setup/tune.