I have a 4K bored 40 thou 10:1 comp 30/65 grind cam not sure duration ported head just curious would twin 40 weber carbs be too much thankful for any advice 

The lovely thing about Webers is that you can change almost everything inside to fit any motor.

You can chase smaller chokes to restrict the airflow down to 1.3L limits and jet it to suit.  You can see from this chart a single or twins are OK.

i have a pair of webers on a manifold for a k series for sale if you're interested. A heaps of jets and emulsion tubes and everything to bolt on and go. Pm me if you're keen