I was doing a timing chain on my 07 f 150 5.4 and was putting roller follower back in and I accidently push the stem down and the keepers came out the stem didn't fall all the way but I can't find the 2 keepers I believe they went down the lower holes in head what do I need to do to get them

 

Get one of those usb cameras (endoscope) and check it out before things get too far. If the keepers are in there you can fish them out with some time and a magnet on flexible shaft. Hope you find nothing in the head and if you do, that you catch it. If I'm following what you are saying the lower holes may be oil drain back holes? If the keepers make it to the oil pan you'll probably be okay.