Lower Ball Joints 67 v's 71 C10

[chevy one]

I found a deal at the bone yard. A 71, 2WD C10 that had upper ball joints, tie rods, rotors, calipers, backing plates, bearings/seals & sway bar with new poly mounts. When I say new, I mean new, never drove down the lane, unless whoever was a complete idiot. Looks like someone started a project and gave up. The new tie rod turn shackles never had bolts installed. All for $60 + tax of course! Spindles are OEM stock height. I only robbed the upper joints. I will be buying quality MOOG lower joints being they hold most of the weight.
When converting from drum to disk using the stock 67 A-arms can I order and install new ball joints for a 71 C10 disk brake setup or do I need to order the ball joints for the 67 arms? Should I have robbed the A-Arms as well? I installed new bushing already in mine last year.
When looking at Rock-Auto they list different part numbers from the 67 to 71. I am assuming this is because of the drum to disk spindle change. Any light that anyone can shed on this would be great.
Thanks