What all is needed to do this in my 03 2500hd 2WD crewcab, auto. how hard is it,would it be worth it? I mainly want it for towing.
Thanks, Charlie

 

The whole motor and its wiring becouse the motor is a touch bigger some of the common wires have trouble stretching.

Why not just get a 408 or 418 LS motor? They both will bolt in no problem, and will probily end up cheaper the a 8.1 including the headaches. Either of those motors are the largest you can buy cheaply with the 408 at about $4000 for a short block.

 

if you do end up doing this, what are your plans for the 6.0? I am looking for a six-ohhhh for my tahoe

 

if ur gonna a reliable tow rig???
get the 8.1 torque monster, also get some longtube since ur gonna have the motor out

 

Are you going to leave the 4L80 behind it? The 8.1L comes with an Allison 1000 in the 2500HD trucks. I am not sure but i think the 8.1L and Dmax also came with the 11.5FF rear and the 6.0 came with the 10.5. Plus there are going to be some suspension upgrades needed as the 8.1L is a heavy pig compared to the 6.0's. PCM, harness, TCM (if your going with an Allison), some suspension upgrades, and time + $$. Should drop right in though considering you are putting it in a 2500HD.