440 69 Cuda Questions

I am buliding a 69 cuda 440 with twin afb's on an old Weiand Manifold # wd20.The carbs are S9131 AFBs .1966 383/440.The motor was tired and knocking.One carb is painted a gold color?The manifold is low profile and has four ports for each carb.Dual plane.
I am on running 1 " carb spacers which are open design with a 3500 stall converter and 4:30 gears.I have rebuilt the motor with .040 over flat top pistons,9.5:1 and a 300H cam.stock 2.08 valves ,new springs to match the cam.This is mainly a weekend street toy.
My questions are
-Does anyone know what the gold paint on the carb indicates?
-Will the open spacers work well with a four port manifold?
-What kind of trap RPMs can I expect in the quarter mile?
-Any idea of quarter mile times.I am running 28" tall 275/60 tires?