1957 chevy 6400 questions ?

[1972k5blazer]

Just bought a 57 6400 gonna be putting it on a newer 3/4 ton 4x4 frame down the road , I want to get rid of the big fenders and put smaller ones on it I seen the upper and lower grill parts are diff and grill is diff and figure I will have to change all that but is everything else the same like the hood is it the same as say a 3100 ? Any thing else I would have to change to put the smaller fenders on it ? Thanks for any help or steer me toward a link please