2004 4.3v6 to 5.3v8 swap

hi all, im new here. ive read through many of your guys forums for years. just never joined till now, anyways. I have a 2004 silverado ls long bed standard cab v6. looking to do the 5.3 v8 swap, current engine has dbc. so a few questions i have are. i want a engine that i dont have to swap a dbw into it. and which year engine should i get so that the harness bolts right in? i just rebuilt the 4l60e in the truck, so that should last long enough till i can afford to buy a 4l80 to put in it. basically just looking for the easiest way to do the v8 swap, from what ive read its pretty straight forward. need the intake tube, coolant hoses, as lines, frame and motor mounts etc. my trans will bolt right up? any help or insite will be greatly appreciated. thanks!