The rockers look like a typical small block, but I hear that they may be a non-adjusting type. The studs look a little smaller at the top, and they were tight for the first 6 turns of removal, then they were loose enough to turn by hand for the next 6 or so turns. Is this a clue as to what they are? What is the correct method of adjusting without losing my distributor index since it is still out.