2015 ram 1500 5.7l motor swap

hello there i just wipped the cam in mt truck and i have been doing some resherch on swaping the motor my self is there any diffrent if i get a motor with the 8 speed trans to the 6 speed anything i need to change from the old motor to the new one like fly wheel pushing where the torque converter sists in side the motor is there a diffrents betweent the 2 motor the motor i am looking at getting is from a 2014 ram 1500 5.7l

thanks