Need help/advise on front suspension

[1969 Project]

Hi guys, I am new to this and hope to get some good info as my buddy recommend that I join. I recently purchased a 1969 c10. They did the front disc brake conv and left the 6 lug pattern on.I purchased a drop kit from EC and I received the 71-72 spindles. I noticed that the outer tie rod is to big to fit into the spindle. I wanted to change my outer tie rods as well as my inner as the inners are shot. That being said in order for me to do this I would need 71-72 tie rods and change the center link to 71-72 as well, correct? Will this affect the Pitman and idler arm as I will be replacing them as well. Also the 71-72 spindles fit the upper and lower ball joints that are in my truck as well, how is this possible? Is my only conclusion to change all of the front end to 71-72? I am not sure what the previous owner did but it seems there are a a lot of mixed parts in my truck. I also found out that the rear end is from a 64-65 17 spline, which does not work with my kit either as I had to order 30 spline side gears, has anyone had to do this?