I'm looking for a donor vehicle with a 4l60e and there are a ton of 4wd tucks but I want 2wd for my swap. Is this a hard conversion?

 

You have to remove every single piece inside the transmission and swap the output shaft.

 

If you had a new(ish) transmission, a good mechanic could swap the output shafts in an hour. Technically you only have to remove the pump and the input drum with reverse drum. The snap ring for the output shaft is then accessible.
The problem with an older transmission is that this disassembly is likely to damage the old teflon sealing rings on the pump and input shaft. These take time to replace. And with the input shaft out, you might as well replace the 3/4 clutch. Etc, etc. It is a slippery slope to a complete rebuild.