Question About Carb On 66 Mustang

Hello,

I recently purchased a 1966 mustang 200i coupe. I had the intentions of restoring it with my father however my father had some medical issues and now for the most part I am left restoring it on my own. I have very little experience working on cars but i am trying to learn. I have a question about the type of carb on the vehicle that i'm hoping someone can assist with. I'm having trouble identifying the type of carb that is on the car. All of the manuals I've read says it comes with an autolite 1100. When i compare the pictures there is a slight difference. It appears there is no thermostat (black knob) In place of that there is a hose. The Carb says holley - list 3715-s. Does anyone know what type of carb this is and the purpose of the hose? The reason I was looking into the carb is because whenever i stop, the car tends to get rough and wants to turn off. If i put it in neutral it runs fine, it only does this when the car is in gear and my foot is on the brake. I have attached pictures.

Thanks in advance
Lamar

I think i found it, looks like its a holley 1909