disc brake conversion

[gfcsteve]

hi all, i searched the forum but didn't find the answer for this. i have a parts truck (1972 5-lug) that has disc brakes and want to put them on my 1969 truck, can i just replace the spindles or do i have to replace the a-arms too. i have already removed the whole assembly from the parts truck(unbolted crossmember and rolled the whole thing out from under the parts truck). it would be easeir to just replace the spindles i think. any comments?

thanks steve