Engine/Transmission (1998.5 - 2002) replacing my 89D250

[89D250]

I'm a builder up in New Hampshire and would like toreplace my D250 with some thing a little newer. I have a chance to purches a 4X4 extended cab 1 ton w/ a utility body. What are the changes from the 2001 to the 2002, and or might there be a less problematic year?

 

[SKneeland]

2001. 5 started rear disc instead of drums

2001. 5 still had the front axle disconnect, not sure if the 02s still did or not

chance of getting a 53 block is less by that time also