5.3/4L60E 4wd Swap Questions

[1972K20]

Ok, I've searched and read and searched and read, I've followed links, looked at build threads, read the pinned threads, PMed other members (thanks for the replies btw!) read sites like http://ls1tech.com and others for the last 3-4 weeks and gone in circles. With all the info out here the last thing I thought I needed to do was start a new thread, but he we go.

My plan is to do this to my 72 K5. I want to retain the original ride height and use the 4L60 w/the NP205. Also, I want to keep the original speedo, tach, oil pressure and amps gauges. My K5 has factory AC, and I want that to work too. I'm undecided on whether to retain the original power brake booster or switch to hydroboost. Any thoughts on that?

So, I decided that I should start looking for a donor engine/tranny to get started. This is where I have some questions.

-First and foremost, what is needed from the donor vehicle to make the swap successful? I know the complete wiring harness and PCM are needed. What else should I look for. I understand that if it's a DBW, I'll need the pedal and the TAC module. Am I forgetting anything here?

-Is there a better year than another when searching for a 5.3?

-When getting an engine from a salvage yard, or some other place where you can't hear it run, how do you determine if the engine is "good" by visual inspection alone?

These are the most basic questions, I know, but I want to make sure I have a good idea of where to start.

Thanks guys!