get the press on spring washer that goes around the shaft, that way if it slips out of the dist it wont go all the way into the pan, use some real heavy long fiber grease, the old time wheel bearing grease to hold shaft in the dist, put the washer up close to the dist so if it falls out you can retrieve it with a magnet, if you get the shaft down to the pump with out it coming loose and the dist wont fall all the way in place just turn engine over with starter or by hand till it does, you wont lose timing because the dist gear will be meshed with the gear on cam, just be sure you get the spring type washer that has the hole in it and teeth all the way around the inside, check with your parts store of ford dealer for the correct washer
