Rubber stopper to pull into place, turn lifter tray over to hold lifter up, wood dowel to hold in place.
I think Joe D wrote the how to, shoud be somewhere here on the TDR. Found it, search is your friend...
Joe Says "The 12” x ½” dowel pins, with chamfer and hacksaw slit in one end, fit snugly into recesses in the tops of the lifters to lift them up against the mushroom feet against the bottom of the lifter bores in the block. You need to make a trough from 2” exhaust pipe to catch the lifters when you pull the dowel out after removing the camshaft. You will use a 36” long ½” dowel with hooks screwed into the ends. The tight hook grabs the string just behind the stopper, and the loose hook pulls out the lifters. You can use a brass tube 3/16” or ¼” diameter, 11. 4” long to help guide the stopper down the right hole in the block. With the engine on a slant from the factory, the stopper tends not to go into the lifter hole. I use a Danco 00 beveled faucet washer, ½” OD, part number 88579, instead of a stopper to fit into the top of the lifter. Procedures and photos appeared in TDR #33, pp. 46-48. "