4 speed conversion. Help or hurt value of car?

This could be true with the younger generation. I am 30 and I notice most of my friends my age or younger can not drive a manual.

I was lucky my dad has a 69 340 4 speed 'Cuda and he insisted I learn drive in it back when I was learning to drive.

Most of my friends had parents who went to the new car lots and bought them new econo-boxes with autos and autos are ever increasing among the newer cars
I hear that. Just seemed to be the thing every since I was young. must have a muscle car with a 4 speed.