Whats the benefits of 5.3 and ls swaps & whats a better choice

[laidoutchevitos]

I've just been reading and seeing post with trucks having these engine swaps. I consider myself a novice/beginner/shade-tree mechanic/ self taught chevy C10 enthusiast. I've started wrenching on a 69 c10 longbed that was given to me all in pieces with buckets of bolts/nuts/screws & wires (which is my 1st pic.) And just started playing with these trucks ever since. I've done total frame swaps all the way to even doing my first paint job. (2nd pic. Blue 72 Cheyenne short bed). Any how well my question is whats the difference & benefits of these engine swaps? A friend of mine keeps telling me he'll sell me a complete 5.3 with everything even tranny for my 70 C10 that already has a sb350 in it. What all would I need to do one of these swaps? And are they difficult to do? Thanks in advance for your feedback. Here's some other pics of some toys that I've had over the years and boy do I kick myself for letting them go.