The answer is NO.. Gambels are pretty jittery/skittish and would need atleast a 2X8X4, I would say.. I just cant imagine putting them in there. I build all my pens pretty large so the size I gave may not be the minimum, but it is probably close.. Gambels, Blue scale, Calis.. high strung birds.
I build mine slightly larger 12" X 12" X 24" if you hatched them and raised them it might turn out different then if you buy grown birds from someone else. gambles can be bribed into settling down, with mealworms every now and then. I have one hen that is really sweet that looks for the mealworms LOL I have used the 10 X 10 size for bobs and coturnix they seemed to be the right size for coturnix but my bobs seem to fit in the 12X12's better