My engine building buddy swears by brazing the pick up in place. I had one come off years ago in my truck but being a gm I was able to make it home with no oil pressure.
Once you properly afix the pick-up to the pump , also ( on press-in tubes ) seal the joint with some oil-proof sealant to prevent the pump from pulling air . If the tube has ever been used , then it is prone to being out-of-round , therefore prone to leaking . DON / fleet 51