74 duster 440 swap

looking good there man .. im putting a big block in my 70 was going to do it with the 72 dart but was told its a little heavy so light a body will be where we go...are the small block and 6 k member the same in the 74??? if so would you be getting rid of the motor mounts...mikepm me if you like im outside of raleigh nc..by the way thats a nice clean car you have do you plan to race it some or street drive it????