65 C10 differential swap questions

[Bills65C10]

Hello fellow C10 lovers. I am new to this forum and am still learning to navigate the site. I still haven't learned how to even post a picture yet, but I am in need of some educated and experienced advise on which way to go on my truck. I can not afford to learn by trial and error. Besides, I'm want to drive my truck......sooner than later.

So, here goes. I've owned a few C10's in my day, but never one this old. It needs updated in a bad way. I have purchased an entire front suspension from a 83 C10 donor truck. I was able to get everything from the firewall forward. I want to convert it to power disk brakes, power steering and convert to 5 lug. I am going to do a static drop for now, so drop spindles and drop springs are in the works. I have a couple questions at this point of collecting parts.

1) What is the best rear end to run in this truck for a better hwy friendly gear ratio? I want between a 308 and a 355 gear ratio with the limited slip I think. I'm going to put a V8 in it eventually I'm sure, but this 230, 6 will have to work for now. So I'm not worried about not having any low end in it right now.
2) What year differentials are the best to run? I know after 70 they are wider, so how does that effect the "trail" of the truck when I'm using a 83 front suspension? I also would like it to bolt up to the stock trailing arms if possible.

My goal is for this to be somewhat of a daily driver. So,an updated drive train is a must. But I want it to be updated in the smartest most logical way. The expertise and combined knowledge on this forum is invaluable, so all input and advise is greatly appreciated.

Thanks,
Bill

I think I figured out how to post a pic. This my truck before I purchased it, but it still looks the same. I'm still gathering parts at this point.