To answer your question, YES many people have put a 5.3 in a 67-72 truck. I am currently putting a 5.3 in my 72. There isn't really a so-called "kit", but there is a TON of information here and over on ls1tech.com. It's good you have the whole truck to start with. You can pull many of the components you need from it, mainly the engine, accessories, pcm, and harness. Yours is probably drive by wire so you will need the throttle pedal and TAC module as well. The items I listed here are what I started with for my swap. Everything else is either reused from your original C10 or pieced together with aftermarket parts. The sky is the limit as far as how much you want to modify these parts. I am trying to stay budget minded so I am leaving things as original as possible and reusing everything that I can, even down to little things like vacuum lines, radiator hoses, etc.
