Idle/fast idle
Ricky, seems I get to your questions first so many times....
Warm idle should be about 900 as you describe, engine and coolant at operating temp, chokes fully open, fast idle cam in the choke housing on the lowest stop.
Fast idle should be, well, whatever it takes for your car to accelerate smoothly from cold idle speed. If the cold engine idle is too low the motor will bog when you gas it. 1300 rpm is okay, but does your engine accelerate smoothly from this speed when cold?
Fast idle is adjustable using the screw on the fast idle cam. The fast idle cam has several (3?) steps on it. It is located inside the cylindrical choke housing on each carb. It were better you didn't mess with it... the setting on each fast idle cam will affect each carb, therefore you must synchronize the fast idle.
If you or someone has messed with these, suggest you remove the cylindrical choke housings (3 little screws each, don't drop 'em), then plop your synchronizer on each carb. Run the engine with the adjustment screw on the same step on each fast idle cam, and check for equal airflow. Adjust as necessary. The adjustment of the fast idle does not affect carb airflow except when the engine is cold, i.e. the throttle plates are controlled by the steps on the fast idle cam.
It is instructive, if you have a spare carb laying around, to play with it and see how the fast idle cam affects throttle plate position.
Rique