Engine differences between auto and manual trans?

I have a low mileage rebuilt /6 that I want to pull from my automatic Valiant and put into my Manual Duster.

Are /6's different between an auto trans and manual trans?

Can I swap an automatic /6 into a manual car easily?

Will the pressure plate bolt to the same spot on crank as the flex plate?

Are the cranks different? Will I need to drill something out or do custom work to do this swap?

Thanks for any advice!