A dished piston 4K,???
A 3K bigport head without the chamber,????
MAybe the 3K head has been machined a lot to bring the comp up on a 3K but it would be unusual to see a 3K bigport head without a chamber as you put it.If you put the two together i would ASSUME that t5he comp RATIO would be around 9:1 dependimng on how big the dishes are in the pistons.