Disc swap, track width, C10 conversion, backspace Q's

[R.O.B.]

I've been searching, but I get conflicting answers, so please bear with me and repeated questions.

I have a 67 C20, going to convert to a C10, 5 lug. I've got 72 lower control arms coming along with 2.5 drop spindles.

So, just change the upper ball joint with a 71-87 correct? And the lower should be correct already, right?
If I keep my C20 drag link, I need to buy which tie rods for the outer, and which adapter sleeves? Or am I mixed up here?

And by converting to disc my front track down will increase, correct?
I'm trying to locate a 71-72 rear, so it's just an easy bolt in 5lug.

So with the conversion in front, and the 71-72 rear, my track width should be the same as a 71-72 C10 correct? Well I can't find the correct numbers, so hopefully someone can answer. I want to purchase 15x8 front wheels, 245/60 tires, and 15x10 rear wheels, 295/50 tires.
I need to figure out the proper backspace for each wheel, so they all square up and look even front to rear.

Rob