verifying Dorman replacement upper control arm part number

[mild68]

Hi, I need some help and confirmation before I order replacement upper control arms and other components as well.

I have a 69 C10 short wheel base frame I am in the process of freshening up the suspension. I believe it already has 73 up disc brake set up on it. I want to order 73 up Upper and lower control arms. My intention is also to get 73 to 87 dropped spindles for HD rotors too.

I found the Dorman numbers 520-181 and 520-182 as the replacements. Are those correct for what I want to do?

In the picture it shows a bracket attached to the ball joint. The arms I have don't have that. They have a slot in the arm for a tab on the brake hose.

I went to the Dorman site, http://www.dormanproducts.com/p-1795...ion&origin=YMM , to verify the number. It shows it is not a fit. Why not?
Do I have the correct numbers? Is some thing wrong with the combo I intend to use?
Also is there a lower control arm assembly available? Part number, please?
Thanks.