Power steering conversion ?

[Jrainman]

I am converting my 1969 c/10 from manual to power steering

After research here on what is needed for a PS conversion , I am coming up with conflicting answers on what Pitman arm to use . some post say use year of truck for pitman arm and other post say match year of power steering gear box with pitman arm.

I have pump side complete , I have a 1980-1987 PS gear box ready to go in ,but unsure of what year -power steering Pitman arm to purchase ....