Tube Control arms

ok so it says :Uses 73-up style big balljoint, 72-older A-body spindles will not work
or can be machined to the larger taper


So What do i have to do to my 71 demon to make just the uppers work i'll lleave the lowers alone then And Do people go rod ends or bushing? Or will i need to get new spindles but what do i have to do wheel wise if i change those???