Carb Idle Question

Carb question

I just bought a 69 Opel GT with a Weber carb on it. The car, when in park, idles at nearly 1500 rpms. When put into gear (auto-transmission) it drops considerably to around 1000 rpms.

My question is this...is it normal for one of these weber 32/36 carbs to idle so high? If I adjust the idle down while in park, it dies when in gear. The previous owner tells me the carb was rebuilt not 200 miles before I purchased the car.

Thanks for any help.