Sounds like old style solids As you look at the lifters as they come out of the lifter blocks You don't see a small spring do you ? I don't think so by your discription Hyd lifters have these springs and the pushrods have the adjusters OK now for adjustment of solid lifters As you roll the engine over watch the travel of let's say the front cyl exhaust pushrod When the pushrod is at the bottom most travel (bottom of the cam lobe) adjust the pushrod so you have a tight spin Proceed to the next pushrod and do the same Adjust always at the low part of the cam