I bought a road bike with drop bars and swist shifters , I come to not like the bars, as I have cronic tension headaches due to my neck muscles never relaxing and the bent over position seems to make it worse and makes my jaws hurt too.

I have a old mnt bike that also has twist shifters on the handlebars. Is it possible to swap the whole handle bar out and use the mnt bike break levers and shifters on the road bike? I know I need to meassure the cable lenghts but if they are long enough I could cut and adjust the tension right?

Only thing is the road bike has 7 rear gears while the mnt bike has 6. But I could do without 7th gear.

Would this idea work?