It sounds like they are hyd lifters. Solids look like little dumb bells. Hyd lifters have a taper about 1/4' from the top and the oil hole is in this area. Some shell style solid lifters have no taper and the oil hole is farther down closer to the bottom. Most 352's are hyd lifter blocks also. But the galleys can be plugged for solids if you wish.

G.