Yes, quite a few. You need to move the trans crossmember backwards on the frame, install a shorter driveshaft (and longer front driveshaft if it's a 4WD), different cooler lines, a few small wiring modifications, and lots of other little things. The hardest part in regards to your '93 will probably be finding someone who can tune the computer to control the 4L80E. You could always install a stand alone controller for it but that's a lot of money, and I know the older TBI PCMs are capable of controlling a 4L80E. I bet someone on the Gearhead EFI forums could help you further with that.
I posted this link on the last page, but here it is again. This is my thread documenting the swap in my red '97 C1500. It has newer electronics than what can be found in your '93 so most of that info will be irrelevant, but reading though the thread should at least give you an idea of what's necessary.
http://www.gmt400.com/threads/97-c1500-4l60e-to-4l80e-swap.38819/