Back when I was a teenager the hot rodders called them "solid lifters", and yes, they were always adjusting their valves. I didn't want any part of them. I had a Crower cam with what they called 8K plus high rev hydraulic lifters, might have been something on the order of the lifters you are talking about here.
Rick Kilpatrick, AAS Automotive Systems Tech, Alamance Community College, Class of 99. 06 5 speed manual Mustang with Pony pkg : GT Mac Mufflers, true duals with one custom pipe. 2.5" system. GT bumper cover, all installed March 7&8 2006. AFE Stage 1 CAI, Motoblue Underdrive pulley, GT aluminum shifter knob, honeycomb rear blackout panel,and dash kit installed. Roush hood scoop and side window louvers installed. SS taillight trim has been installed, new alum. GT steering wheel installed.